Why does Returnal drop from 85 to 42 FPS on ASRock A320M-ITX?

I felt completely defeated when my frame rate plummeted from 85 to 42 FPS during intense loop battles, making the controls feel disjointed. I first tried disabling all power-saving options in the BIOS, but it didn't stop the drops and actually caused idle temperatures to spike from 35℃ to 52℃ per AIDA64. I then used the GamePP Power Plan Switcher to lock the system into High Performance mode and optimized process priorities. The 1% low FPS rose from 31 to 56 per RTSS, and VRM temperatures stayed stable at 54-60℃ per AIDA64, while voltage stabilized at 1.15-1.20V per HWiNFO64.