While working on a heart rate measurement app (photoplethysmography via camera), we faced systematic err=-17281 (FigCaptureSourceRemote) issues on real devices starting from iOS 17+, and the problem became more noticeable after iOS 26. The error often appeared during AVCaptureSession initialization or when restarting capture, especially under high frame rates (30-60 FPS) and frequent foreground/background transitions. Root cause (our understanding): Camera hardware/session not fully released after previous use Race conditions between session teardown and new setup Changes in AVFoundation capture pipeline in recent iOS versions Our solution: Instead of blocking delays, we implemented asynchronous retry logic with explicit hardware readiness check via AVCaptureDevice.lockForConfiguration().