diff --git a/.claude/settings.local.json b/.claude/settings.local.json
index 5a029ab..32e701d 100644
--- a/.claude/settings.local.json
+++ b/.claude/settings.local.json
@@ -125,7 +125,16 @@
       "Bash(python /tmp/apply_guards.py)",
       "Bash(python /tmp/apply_all_guards.py)",
       "Bash(python /tmp/cleanup_redundant_checks.py)",
-      "Bash(python /tmp/final_cleanup.py)"
+      "Bash(python /tmp/final_cleanup.py)",
+      "Bash(grep -n \"ANSFRBase\" /c/Projects/CLionProjects/ANSCORE/modules/ANSODEngine/*.h /c/Projects/CLionProjects/ANSCORE/modules/ANSODEngine/*.cpp)",
+      "Bash(grep -n \"class.*public ANSFRBase\\\\|class.*: public ANSFRBase\" /c/Projects/CLionProjects/ANSCORE/modules/ANSODEngine/*.h)",
+      "Bash(grep -n \"class.*public.*FaceDetector\\\\|class.*public ANSFDBase\\\\|struct.*public\" /c/Projects/CLionProjects/ANSCORE/modules/ANSODEngine/*.h)",
+      "Bash(grep -l \"ANSFRBase\" /c/Projects/CLionProjects/ANSCORE/modules/ANSODEngine/*.h)",
+      "Bash(grep -rn \"public ANSFRBase\" /c/Projects/CLionProjects/ANSCORE/modules/ANSODEngine/*.h)",
+      "Bash(python /tmp/apply_fd_guards.py)",
+      "Bash(python /tmp/apply_fd_precheck.py)",
+      "Bash(ls /c/Projects/CLionProjects/ANSCORE/modules/ANSFR/*.cpp /c/Projects/CLionProjects/ANSCORE/modules/ANSFR/*.h)",
+      "Bash(grep -rn \"lock_guard.*_mutex\\\\|lock_guard.*mutex\" /c/Projects/CLionProjects/ANSCORE/modules/ANSFR/*.cpp)"
     ]
   }
 }
diff --git a/modules/ANSFR/ANSFaceRecognizer.cpp b/modules/ANSFR/ANSFaceRecognizer.cpp
index 012af8d..b80ef53 100644
--- a/modules/ANSFR/ANSFaceRecognizer.cpp
+++ b/modules/ANSFR/ANSFaceRecognizer.cpp
@@ -44,6 +44,11 @@ namespace ANSCENTER {
 		const std::string& modelZipPassword,
 		std::string& labelMap)
 	{
+		struct LoadGuard {
+			std::atomic<bool>& f;
+			explicit LoadGuard(std::atomic<bool>& fl) : f(fl) { f.store(true); }
+			~LoadGuard() { f.store(false); }
+		} mlg(_modelLoading);
 		ANS_DBG("FaceRecognizer", "Initialize: modelZip=%s", modelZipFilePath.c_str());
 		bool result = ANSFRBase::Initialize(licenseKey, modelConfig, modelZipFilePath, modelZipPassword, labelMap);
 		if (!result) {
@@ -276,7 +281,9 @@ namespace ANSCENTER {
 			return embeddingResult;
 		}
 
-		std::lock_guard<std::recursive_mutex> lock(_mutex);
+		if (_modelLoading.load()) return embeddingResult;
+		auto lock = TryLockWithTimeout("ANSFaceRecognizer::Feature");
+		if (!lock.owns_lock()) return embeddingResult;
 
 		try {
 			if (engineType == EngineType::NVIDIA_GPU) {
@@ -338,7 +345,9 @@ namespace ANSCENTER {
 			return resultObjects;
 		}
 
-		std::lock_guard<std::recursive_mutex> lock(_mutex);
+		if (_modelLoading.load()) return resultObjects;
+		auto lock = TryLockWithTimeout("ANSFaceRecognizer::Match");
+		if (!lock.owns_lock()) return resultObjects;
 
 		if (!_isInitialized) {
 			_logger.LogError("ANSFaceRecognizer::Match",
diff --git a/modules/ANSFR/ANSFaceRecognizer.h b/modules/ANSFR/ANSFaceRecognizer.h
index e24266e..32992f4 100644
--- a/modules/ANSFR/ANSFaceRecognizer.h
+++ b/modules/ANSFR/ANSFaceRecognizer.h
@@ -11,6 +11,9 @@
 #include <faiss/gpu/GpuIndexFlat.h>
 #include <faiss/gpu/StandardGpuResources.h>
 #include <unordered_map>
+#include <atomic>
+#include <chrono>
+#include <thread>
 #include "engine.h"
 #include "engine/EnginePoolManager.h"
 #include "ONNXEngine.h"
@@ -99,6 +102,28 @@ namespace ANSCENTER {
         const bool NORMALIZE = true;
 
         std::recursive_mutex _mutex;
+        std::atomic<bool>    _modelLoading{ false };
+
+        std::unique_lock<std::recursive_mutex> TryLockWithTimeout(
+                const char* caller, unsigned int timeoutMs = 5000)
+        {
+            const auto deadline = std::chrono::steady_clock::now()
+                                + std::chrono::milliseconds(timeoutMs);
+            std::unique_lock<std::recursive_mutex> lk(_mutex, std::defer_lock);
+            while (!lk.try_lock()) {
+                if (std::chrono::steady_clock::now() >= deadline) {
+                    _logger.LogWarn(caller,
+                        "Mutex acquisition timed out after "
+                        + std::to_string(timeoutMs) + " ms"
+                        + (_modelLoading.load() ? " (model loading in progress)" : ""),
+                        __FILE__, __LINE__);
+                    return lk;
+                }
+                std::this_thread::sleep_for(std::chrono::milliseconds(1));
+            }
+            return lk;
+        }
+
         float m_knownPersonThresh = 0.35f;
         EngineType engineType;
 
diff --git a/modules/ANSOCR/ANSCpuOCR.cpp b/modules/ANSOCR/ANSCpuOCR.cpp
index 7d0964e..2bb99b3 100644
--- a/modules/ANSOCR/ANSCpuOCR.cpp
+++ b/modules/ANSOCR/ANSCpuOCR.cpp
@@ -212,7 +212,9 @@ namespace ANSCENTER {
 		return RunInference(input, "OCRCPUCAM");
 	}
 	std::vector<ANSCENTER::OCRObject> ANSCPUOCR::RunInference(const cv::Mat& input, const std::string& cameraId) {
-		std::lock_guard<std::mutex> lock(_mutex);
+		if (_modelLoading.load()) return {};
+		auto lock = TryLockWithTimeout("ANSCPUOCR::RunInference");
+		if (!lock.owns_lock()) return {};
 
 		// Early validation
 		if (!_licenseValid) {
@@ -311,7 +313,9 @@ namespace ANSCENTER {
 	}
 
 	std::vector<ANSCENTER::OCRObject> ANSCPUOCR::RunInference(const cv::Mat& input, const std::vector<cv::Rect>& Bbox) {
-		std::lock_guard<std::mutex> lock(_mutex);
+		if (_modelLoading.load()) return {};
+		auto lock = TryLockWithTimeout("ANSCPUOCR::RunInference(Bbox)");
+		if (!lock.owns_lock()) return {};
 
 		// Early validation
 		if (!_licenseValid) {
@@ -434,7 +438,9 @@ namespace ANSCENTER {
 		const std::vector<cv::Rect>& Bbox,
 		const std::string& cameraId)
 	{
-		std::lock_guard<std::mutex> lock(_mutex);
+		if (_modelLoading.load()) return {};
+		auto lock = TryLockWithTimeout("ANSCPUOCR::RunInference(Bbox,CamId)");
+		if (!lock.owns_lock()) return {};
 
 		// Early validation
 		if (!_licenseValid) {
diff --git a/modules/ANSOCR/ANSCpuOCR.h b/modules/ANSOCR/ANSCpuOCR.h
index 21a2357..3613a29 100644
--- a/modules/ANSOCR/ANSCpuOCR.h
+++ b/modules/ANSOCR/ANSCpuOCR.h
@@ -6,6 +6,9 @@
 #include "opencv2/imgproc.hpp"
 #include <iostream>
 #include <vector>
+#include <atomic>
+#include <chrono>
+#include <thread>
 #include "LabVIEWHeader/extcode.h"
 #include "ANSLicense.h"
 #include "ANSOCRBase.h"
@@ -25,8 +28,30 @@ namespace ANSCENTER {
 	private:
 		std::unique_ptr<PaddleOCR::PPOCR> ppocr = std::make_unique<PaddleOCR::PPOCR>();
 		std::mutex    _mutex;
+		std::atomic<bool> _modelLoading{ false };
 		cv::Mat _frameBuffer;  // Reusable buffer for color conversion
 
+		// Try to lock _mutex with a timeout for non-recursive mutex
+		std::unique_lock<std::mutex> TryLockWithTimeout(
+				const char* caller, unsigned int timeoutMs = 5000)
+		{
+			const auto deadline = std::chrono::steady_clock::now()
+								+ std::chrono::milliseconds(timeoutMs);
+			std::unique_lock<std::mutex> lk(_mutex, std::defer_lock);
+			while (!lk.try_lock()) {
+				if (std::chrono::steady_clock::now() >= deadline) {
+					_logger.LogWarn(caller,
+						"Mutex acquisition timed out after "
+						+ std::to_string(timeoutMs) + " ms"
+						+ (_modelLoading.load() ? " (model loading in progress)" : ""),
+						__FILE__, __LINE__);
+					return lk;
+				}
+				std::this_thread::sleep_for(std::chrono::milliseconds(1));
+			}
+			return lk;
+		}
+
 	};
 }
 #endif
diff --git a/modules/ANSOCR/ANSONNXOCR/PaddleOCRV5Engine.cpp b/modules/ANSOCR/ANSONNXOCR/PaddleOCRV5Engine.cpp
index 22582f2..9216154 100644
--- a/modules/ANSOCR/ANSONNXOCR/PaddleOCRV5Engine.cpp
+++ b/modules/ANSOCR/ANSONNXOCR/PaddleOCRV5Engine.cpp
@@ -13,6 +13,7 @@ bool PaddleOCRV5Engine::Initialize(const std::string& detModelPath,
                                     const std::string& recModelPath,
                                     const std::string& dictPath) {
     std::lock_guard<std::recursive_mutex> lock(_mutex);
+    ModelLoadingGuard mlg(_modelLoading);
 
     try {
         // Initialize detector (also triggers EPLoader init in BasicOrtHandler)
@@ -59,13 +60,16 @@ bool PaddleOCRV5Engine::Initialize(const std::string& detModelPath,
 }
 
 std::vector<OCRPredictResult> PaddleOCRV5Engine::ocr(const cv::Mat& img) {
-    std::lock_guard<std::recursive_mutex> lock(_mutex);
+    if (_modelLoading.load()) return {};
 
     std::vector<OCRPredictResult> results;
 
-    if (!_initialized || img.empty()) {
-        return results;
+    {
+        auto lk = TryLockWithTimeout("PaddleOCRV5Engine::ocr");
+        if (!lk.owns_lock()) return results;
+        if (!_initialized || img.empty()) return results;
     }
+    // _mutex released — heavy pipeline runs lock-free
 
     // Step 1: Text Detection
     auto boxes = detector_->Detect(img, _maxSideLen, _detDbThresh, _detBoxThresh, _detUnclipRatio, _useDilation);
@@ -127,8 +131,12 @@ std::vector<OCRPredictResult> PaddleOCRV5Engine::ocr(const cv::Mat& img) {
 }
 
 TextLine PaddleOCRV5Engine::recognizeOnly(const cv::Mat& croppedImage) {
-    std::lock_guard<std::recursive_mutex> lock(_mutex);
-    if (!_initialized || !recognizer_ || croppedImage.empty()) return { "", 0.0f };
+    if (_modelLoading.load()) return { "", 0.0f };
+    {
+        auto lk = TryLockWithTimeout("PaddleOCRV5Engine::recognizeOnly");
+        if (!lk.owns_lock()) return { "", 0.0f };
+        if (!_initialized || !recognizer_ || croppedImage.empty()) return { "", 0.0f };
+    }
     return recognizer_->Recognize(croppedImage);
 }
 
diff --git a/modules/ANSOCR/ANSONNXOCR/PaddleOCRV5Engine.h b/modules/ANSOCR/ANSONNXOCR/PaddleOCRV5Engine.h
index a99e53f..a7ec21f 100644
--- a/modules/ANSOCR/ANSONNXOCR/PaddleOCRV5Engine.h
+++ b/modules/ANSOCR/ANSONNXOCR/PaddleOCRV5Engine.h
@@ -7,6 +7,9 @@
 
 #include <memory>
 #include <mutex>
+#include <atomic>
+#include <chrono>
+#include <thread>
 #include <string>
 #include <vector>
 
@@ -48,6 +51,37 @@ private:
     std::unique_ptr<ONNXOCRRecognizer>  recognizer_;
 
     std::recursive_mutex _mutex;
+    std::atomic<bool>    _modelLoading{ false };
+
+    // RAII helper: sets _modelLoading=true on construction, false on destruction.
+    struct ModelLoadingGuard {
+        std::atomic<bool>& flag;
+        explicit ModelLoadingGuard(std::atomic<bool>& f) : flag(f) { flag.store(true); }
+        ~ModelLoadingGuard() { flag.store(false); }
+        ModelLoadingGuard(const ModelLoadingGuard&) = delete;
+        ModelLoadingGuard& operator=(const ModelLoadingGuard&) = delete;
+    };
+
+    // Try to lock _mutex with a timeout.  Returns a unique_lock that
+    // evaluates to true on success.
+    std::unique_lock<std::recursive_mutex> TryLockWithTimeout(
+            const char* caller, unsigned int timeoutMs = 5000)
+    {
+        const auto deadline = std::chrono::steady_clock::now()
+                            + std::chrono::milliseconds(timeoutMs);
+        std::unique_lock<std::recursive_mutex> lk(_mutex, std::defer_lock);
+        while (!lk.try_lock()) {
+            if (std::chrono::steady_clock::now() >= deadline) {
+                std::cerr << "[" << caller << "] Mutex acquisition timed out after "
+                          << timeoutMs << " ms"
+                          << (_modelLoading.load() ? " (model loading in progress)" : "")
+                          << std::endl;
+                return lk; // unlocked
+            }
+            std::this_thread::sleep_for(std::chrono::milliseconds(1));
+        }
+        return lk; // locked
+    }
 
     // Detection parameters
     int   _maxSideLen    = kDetMaxSideLen;
diff --git a/modules/ANSOCR/ANSRTOCR/PaddleOCRV5RTEngine.cpp b/modules/ANSOCR/ANSRTOCR/PaddleOCRV5RTEngine.cpp
index 5313a96..283178e 100644
--- a/modules/ANSOCR/ANSRTOCR/PaddleOCRV5RTEngine.cpp
+++ b/modules/ANSOCR/ANSRTOCR/PaddleOCRV5RTEngine.cpp
@@ -12,6 +12,7 @@ bool PaddleOCRV5RTEngine::Initialize(const std::string& detModelPath,
                                       int gpuId,
                                       const std::string& engineCacheDir) {
     std::lock_guard<std::recursive_mutex> lock(_mutex);
+    ModelLoadingGuard mlg(_modelLoading);
 
     gpuId_ = gpuId;
     if (!engineCacheDir.empty()) {
@@ -57,10 +58,15 @@ bool PaddleOCRV5RTEngine::Initialize(const std::string& detModelPath,
 }
 
 std::vector<OCRPredictResult> PaddleOCRV5RTEngine::ocr(const cv::Mat& image) {
-    std::lock_guard<std::recursive_mutex> lock(_mutex);
-    std::vector<OCRPredictResult> results;
+    if (_modelLoading.load()) return {};
 
-    if (!detector_ || !recognizer_ || image.empty()) return results;
+    std::vector<OCRPredictResult> results;
+    {
+        auto lk = TryLockWithTimeout("PaddleOCRV5RTEngine::ocr");
+        if (!lk.owns_lock()) return results;
+        if (!detector_ || !recognizer_ || image.empty()) return results;
+    }
+    // _mutex released — heavy pipeline runs lock-free
 
     try {
         // 1. Detection: find text boxes
@@ -148,8 +154,12 @@ std::vector<OCRPredictResult> PaddleOCRV5RTEngine::ocr(const cv::Mat& image) {
 }
 
 TextLine PaddleOCRV5RTEngine::recognizeOnly(const cv::Mat& croppedImage) {
-    std::lock_guard<std::recursive_mutex> lock(_mutex);
-    if (!recognizer_ || croppedImage.empty()) return { "", 0.0f };
+    if (_modelLoading.load()) return { "", 0.0f };
+    {
+        auto lk = TryLockWithTimeout("PaddleOCRV5RTEngine::recognizeOnly");
+        if (!lk.owns_lock()) return { "", 0.0f };
+        if (!recognizer_ || croppedImage.empty()) return { "", 0.0f };
+    }
     return recognizer_->Recognize(croppedImage);
 }
 
diff --git a/modules/ANSOCR/ANSRTOCR/PaddleOCRV5RTEngine.h b/modules/ANSOCR/ANSRTOCR/PaddleOCRV5RTEngine.h
index 929952b..1254b5c 100644
--- a/modules/ANSOCR/ANSRTOCR/PaddleOCRV5RTEngine.h
+++ b/modules/ANSOCR/ANSRTOCR/PaddleOCRV5RTEngine.h
@@ -6,6 +6,9 @@
 #include "RTOCRRecognizer.h"
 #include <memory>
 #include <mutex>
+#include <atomic>
+#include <chrono>
+#include <thread>
 #include <string>
 #include <vector>
 #include "ANSLicense.h"
@@ -64,6 +67,34 @@ private:
     std::string engineCacheDir_;
 
     std::recursive_mutex _mutex;
+    std::atomic<bool>    _modelLoading{ false };
+
+    struct ModelLoadingGuard {
+        std::atomic<bool>& flag;
+        explicit ModelLoadingGuard(std::atomic<bool>& f) : flag(f) { flag.store(true); }
+        ~ModelLoadingGuard() { flag.store(false); }
+        ModelLoadingGuard(const ModelLoadingGuard&) = delete;
+        ModelLoadingGuard& operator=(const ModelLoadingGuard&) = delete;
+    };
+
+    std::unique_lock<std::recursive_mutex> TryLockWithTimeout(
+            const char* caller, unsigned int timeoutMs = 5000)
+    {
+        const auto deadline = std::chrono::steady_clock::now()
+                            + std::chrono::milliseconds(timeoutMs);
+        std::unique_lock<std::recursive_mutex> lk(_mutex, std::defer_lock);
+        while (!lk.try_lock()) {
+            if (std::chrono::steady_clock::now() >= deadline) {
+                std::cerr << "[" << caller << "] Mutex acquisition timed out after "
+                          << timeoutMs << " ms"
+                          << (_modelLoading.load() ? " (model loading in progress)" : "")
+                          << std::endl;
+                return lk;
+            }
+            std::this_thread::sleep_for(std::chrono::milliseconds(1));
+        }
+        return lk;
+    }
 };
 
 } // namespace rtocr
diff --git a/modules/ANSODEngine/ANSEngineCommon.h b/modules/ANSODEngine/ANSEngineCommon.h
index 04aefe9..327b0b3 100644
--- a/modules/ANSODEngine/ANSEngineCommon.h
+++ b/modules/ANSODEngine/ANSEngineCommon.h
@@ -1046,6 +1046,46 @@ namespace ANSCENTER
         MoveDetectsHandler          _handler;
         const size_t     QUEUE_SIZE = 10;
         std::recursive_mutex	    _mutex;
+        std::atomic<bool>           _modelLoading{ false };
+
+        // Pre-inference gate for ANSFDBase subclasses
+        bool PreInferenceCheck(const char* caller) {
+            if (_modelLoading.load()) return false;
+            auto lk = TryLockWithTimeout(caller);
+            if (!lk.owns_lock()) return false;
+            if (!_licenseValid || !_isInitialized)
+                return false;
+            return true;
+        }
+
+        struct ModelLoadingGuard {
+            std::atomic<bool>& flag;
+            explicit ModelLoadingGuard(std::atomic<bool>& f) : flag(f) { flag.store(true); }
+            ~ModelLoadingGuard() { flag.store(false); }
+            ModelLoadingGuard(const ModelLoadingGuard&) = delete;
+            ModelLoadingGuard& operator=(const ModelLoadingGuard&) = delete;
+        };
+
+        std::unique_lock<std::recursive_mutex> TryLockWithTimeout(
+                const char* caller, unsigned int timeoutMs = 5000)
+        {
+            const auto deadline = std::chrono::steady_clock::now()
+                                + std::chrono::milliseconds(timeoutMs);
+            std::unique_lock<std::recursive_mutex> lk(_mutex, std::defer_lock);
+            while (!lk.try_lock()) {
+                if (std::chrono::steady_clock::now() >= deadline) {
+                    _logger.LogWarn(caller,
+                        "Mutex acquisition timed out after "
+                        + std::to_string(timeoutMs) + " ms"
+                        + (_modelLoading.load() ? " (model loading in progress)" : ""),
+                        __FILE__, __LINE__);
+                    return lk;
+                }
+                std::this_thread::sleep_for(std::chrono::milliseconds(1));
+            }
+            return lk;
+        }
+
         ANSCENTER::EngineType	    engineType;
 
         bool                        _facelivenessEngineValid{ false };
diff --git a/modules/ANSODEngine/ANSOVFBFaceDetector.cpp b/modules/ANSODEngine/ANSOVFBFaceDetector.cpp
index d71d2fa..09e4ce1 100644
--- a/modules/ANSODEngine/ANSOVFBFaceDetector.cpp
+++ b/modules/ANSODEngine/ANSOVFBFaceDetector.cpp
@@ -99,6 +99,7 @@ namespace ANSCENTER {
         std::vector<Object> output;
         output.clear();
         if (!_licenseValid) {
+    	if (_modelLoading.load()) return {};
             this->_logger.LogError("ANSOVFBFD::RunInference", "Invalid license", __FILE__, __LINE__);
             return output;
         }
@@ -180,6 +181,7 @@ namespace ANSCENTER {
         std::vector<Object> output;
         output.clear();
         if (!_licenseValid) {
+    	if (_modelLoading.load()) return {};
             this->_logger.LogError("ANSOVFBFD::RunInference", "Invalid license", __FILE__, __LINE__);
             return output;
         }
diff --git a/modules/ANSODEngine/ANSOVFaceDetector.cpp b/modules/ANSODEngine/ANSOVFaceDetector.cpp
index c159b54..d43190c 100644
--- a/modules/ANSODEngine/ANSOVFaceDetector.cpp
+++ b/modules/ANSODEngine/ANSOVFaceDetector.cpp
@@ -102,6 +102,7 @@ namespace ANSCENTER {
     std::vector<Object> ANSOVFD::RunInference(const cv::Mat& input, const std::string& camera_id, bool useDynamicImage, bool validateFace, bool facelivenessCheck) {
         // ── DML device-lost recovery (outside mutex) ──────────────
         if (_dmlDeviceLost && _face_detector) {
+    	if (_modelLoading.load()) return {};
             // The DML session is broken — recreate on CPU
             try {
                 auto cpuDetector = std::make_unique<ANSCENTER::SCRFD>(
@@ -136,6 +137,7 @@ namespace ANSCENTER {
     std::vector<Object> ANSOVFD::RunInference(const cv::Mat& input, bool useDynamicImage, bool validateFace, bool facelivenessCheck) {
         // ── DML device-lost recovery (outside mutex) ──────────────
         if (_dmlDeviceLost && _face_detector) {
+    	if (_modelLoading.load()) return {};
             try {
                 auto cpuDetector = std::make_unique<ANSCENTER::SCRFD>(
                     _scrfdModelPath, ANSCENTER::EngineType::CPU);
diff --git a/modules/ANSODEngine/CNNFaceDetector.cpp b/modules/ANSODEngine/CNNFaceDetector.cpp
index 89ac753..6bbade5 100644
--- a/modules/ANSODEngine/CNNFaceDetector.cpp
+++ b/modules/ANSODEngine/CNNFaceDetector.cpp
@@ -73,6 +73,7 @@ namespace ANSCENTER {
         std::vector<Object> output;
         output.clear();
         if (!_licenseValid) {
+    	if (_modelLoading.load()) return {};
             this->_logger.LogError("ANSCNNFD::RunInference", "Invalid license", __FILE__, __LINE__);
             return output;
         }
diff --git a/modules/ANSODEngine/RetinaFaceDetector.cpp b/modules/ANSODEngine/RetinaFaceDetector.cpp
index d5eff3d..3dadc15 100644
--- a/modules/ANSODEngine/RetinaFaceDetector.cpp
+++ b/modules/ANSODEngine/RetinaFaceDetector.cpp
@@ -114,6 +114,7 @@ namespace ANSCENTER {
         std::vector<Object> output;
         output.clear();
         if (!_licenseValid) {
+    	if (_modelLoading.load()) return {};
             this->_logger.LogError("ANSRETINAFD::RunInference", "Invalid license", __FILE__, __LINE__);
             return output;
         }
@@ -184,6 +185,7 @@ namespace ANSCENTER {
         std::vector<Object> output;
         output.clear();
         if (!_licenseValid) {
+    	if (_modelLoading.load()) return {};
             this->_logger.LogError("ANSRETINAFD::RunInference", "Invalid license", __FILE__, __LINE__);
             return output;
         }
diff --git a/modules/ANSODEngine/SCRFDFaceDetector.cpp b/modules/ANSODEngine/SCRFDFaceDetector.cpp
index ca65172..53617ed 100644
--- a/modules/ANSODEngine/SCRFDFaceDetector.cpp
+++ b/modules/ANSODEngine/SCRFDFaceDetector.cpp
@@ -223,12 +223,14 @@ namespace ANSCENTER {
 		bool useDynamicImage,
 		bool validateFace)
 	{
+		if (_modelLoading.load()) return {};
 		// Phase 1: Validation + image preprocessing (brief lock)
 		cv::Mat im;
 		bool croppedFace;
 		float scoreThreshold;
 		{
-			std::lock_guard<std::recursive_mutex> lock(_mutex);
+			auto lock = TryLockWithTimeout("ANSSCRFDFD::Inference");
+			if (!lock.owns_lock()) return {};
 
 			if (!_licenseValid) {
 				_logger.LogError("ANSSCRFDFD::Inference", "Invalid license", __FILE__, __LINE__);
@@ -411,7 +413,9 @@ namespace ANSCENTER {
 
 
 	std::vector<Object> ANSSCRFDFD::InferenceDynamic(const cv::Mat& input, const std::string& camera_id) {
-		std::lock_guard<std::recursive_mutex> lock(_mutex);
+		if (_modelLoading.load()) return {};
+		auto lock = TryLockWithTimeout("ANSSCRFDFD::InferenceDynamic");
+		if (!lock.owns_lock()) return {};
 		std::vector<Object> output;
 
 		try {
diff --git a/modules/ANSODEngine/SCRFDOVFaceDetector.cpp b/modules/ANSODEngine/SCRFDOVFaceDetector.cpp
index d3b284c..7480bb7 100644
--- a/modules/ANSODEngine/SCRFDOVFaceDetector.cpp
+++ b/modules/ANSODEngine/SCRFDOVFaceDetector.cpp
@@ -218,6 +218,7 @@ namespace ANSCENTER {
         std::vector<Object> outputs;
         outputs.clear();
         if (!_licenseValid) {
+    	if (_modelLoading.load()) return {};
             this->_logger.LogError("ANSOVSCRFDFD::RunInference", "Invalid license", __FILE__, __LINE__);
             return outputs;
         }