It only happens with the TensorRT engine of Rife, the ncnn/Vulcan version works fine but my gpu can't handle it (RTX 3080)
It happens with full movie UHD Bluray mkv rips of several of the Fast & Furious and Transformers movies and some others.
I have an RTX 4080 and full 4K movies cannot run at 48fps+ smoothly, not even on RTX 4090 afaik. If they have HDR data, even worse. I only have a 1080p screen, but I've seen people here recommending to downscale the resolution to 1440p or something similar. Tried your clip and it seems to be running at less than 24 fps (maybe 12 fps) on my RTX 4080 when enabling RIFE (TRT or Vulkan, doesn't matetr). The video gets stretched to twice the normal duration for some reason, and the sound stops in the middle of the video. Not sure what's going on with your optimization window though. Mine ran fine, saved the profile in ~40 seconds.