How to fix FPS drops from 90 to 45 in House Flipper Remastered?

While riding through Hydra Village, the frame rate suddenly drops from 90 to 45, which severely ruins the handling feel. I tried enabling the Windows High Performance power plan; it only added 3 average FPS while 1% lows remained terrible, which felt like a superficial fix. I used the GamePP Resource Scheduler to set the game process priority to Realtime and closed all background sync services. RTSS showed frame generation time converged to 11-16ms, and AIDA64 confirmed CPU temperature stable at 68-75℃, with clocks at 3.6-3.8GHz via GamePP Performance Analysis.