Why does frame rate fluctuate in Gray Zone Warfare melee combat on AMD Ryzen 5 5600?

Aiming was impossible when the frame rate dropped from 240 to 120 FPS. I tried lowering shadow quality from Ultra to High, but the visual loss was too significant for my taste. I then used GamePP Resource Scheduler to set the game process priority to Real-time and monitored VRAM bandwidth utilization. RTSS frame time monitoring showed the interval converged from 4-15ms to 3-4ms. GPU temperature stayed stable at 62-68℃ per AIDA64. This precise configuration was the best way to set my performance back to normal.