Why do I get random 40 FPS drops in Gray Zone jungle scenes?

During long-range sniping, my frame rate would randomly drop to 40, making every engagement feel uncertain. I tried enabling Hardware-Accelerated GPU Scheduling in Windows; it looked fine in settings, but the drops persisted, proving software tweaks couldn't fix hardware volatility. I used the GamePP DLSS/FSR Image Sampling Calibrator to lock the sampling rate to Quality mode. AIDA64 showed a stable frequency line, and HWMonitor confirmed GPU temps at 65-72℃ with voltage locked at 0.92-0.98V, while GPU-Z tracked 2100-2400MHz.