Why does my FPS drop from 144 to 80 during base infiltration?

While infiltrating a base, my FPS suddenly tanked from 144 to 80, which made me incredibly anxious about my system's stability. I tried lowering graphics from Medium to Low; while temps dropped 4℃ per AIDA64, the loss of detail was just unacceptable. I used the GamePP Fan Curve Configuration Panel to lock the 70-85℃ range at 1700 RPM and enabled the High Performance power plan. RTSS showed frame time fluctuations narrowed from 6-22ms to 5-8ms, and Cinebench R23 confirmed stable multi-core frequencies.