Why does my game freeze for 0.4s while stealthing in forests?

It's devastating when you're tracking prey in a valley and the screen freezes for 0.4 seconds, spooking the animal instantly. I first tried disabling power-saving options in the BIOS, but it didn't stop the drops and actually pushed my idle temps from 32℃ to 48℃. I eventually used the GamePP Power Plan Switcher to lock the system into High Performance mode and synced the process priority. RTSS monitoring showed the 1% low FPS jumped from 38 to 62, while GPU-Z measured temps at 52-58℃ and HWInfo showed stable voltage at 0.91-0.98V.