Why does FPS drop from 80 to 20 during dimensional jumps in Rift Apart?

It's unbelievable—during the coolest dimensional jumps, the game turns into a slideshow. I tried lowering the graphics to Medium, but the image became blurry and the stuttering persisted, making me feel like I was wasting my hardware. I used the GamePP Resource Scheduler to set the process priority to Realtime and restricted background update services. RTSS showed frame times were suppressed to 16-24ms, and HWiNFO recorded memory temperatures between 52-60℃.