Why does Tales of Arise randomly drop to 30 FPS in open world?

While exploring the vast map, the frame rate would randomly drop to 30 FPS, making me feel very hesitant during gameplay. I ran the Windows Memory Diagnostic tool, which showed everything was normal, but the drops persisted—software tests couldn't detect hardware fluctuations. I used the GamePP BIOS Load-Line Voltage Adjustment Wizard to lock memory voltage at 1.28V and VCCSA at 1.15V per HWInfo. AIDA64 stress tests showed a flat line for stability at 1.28V.