Why does Black Myth: Wukong drop from 60 to 45 FPS with Crucial DDR4 3200MHz 8GB in group battles?

Frame drops to 45 FPS in group battles were painful. I tried increasing page file, but it made it worse. I adjusted memory timing to 15-15-15-38 and voltage to 1.25V in GamePP. Memory temp stabilized at 46-52℃. VRM held at 58-63℃. MemTest86 showed zero errors. The frame rate is now locked and stable.