Why does Black Desert Remastered drop to 15 FPS in towns on ASRock B450M-HDV?

I can't stand it; every time I enter Heidel, the frame rate drops from 80 to 15 per RTSS, making me want to uninstall the game. I tried enabling High Performance mode in Windows, but CPU temperature hit 92℃ and the drops remained, which was an infuriating waste of time. I used the GamePP BIOS Load-Line Voltage Adjustment Wizard to manually set Vcore to 1.32-1.35V and LL to L2 mode. Cinebench R23 multi-core score rose to 11800 points, and CPU temperature stabilized at 75-82℃ per HWiNFO.