Why does my FPS drop from 60 to 30 in Metaphor: ReFantazio?

I was disgusted when flashy combat animations triggered massive frame drops from 60 to 30 FPS. I first tried lowering all in-game visual effects, but the graphics became primitive while the drops remained. I used the GamePP Power Plan Switcher to force Extreme Performance and disabled C-State in BIOS. RTSS showed average FPS rose from 38 to 55, and CPU-Z confirmed the frequency locked at 3.6GHz. No more plummeting frames during battles.