Hello, I have a problem with Warp Stabilizer (Windows). The last working version is 18.4.6. In all subsequent versions, this effect no longer works as before. Once the video has been analyzed and stabilized, the video shakes wildly and includes some green frames. It looks like the effect jumps back a second, and then it messes with the stabilization. I can recreate it with almost any video. Created with iPhone 11, FilmicPro, 50fps 4K. Adobe support couldn't help me, I should first delete everything again, remove the profile and so on. The effect works perfectly in all older versions. System: Windows 11, 64GB RAM, Geforce RTX 3080.
Probably this is caused by the grpahics card decoding acceleration of compressed video. Try a couple of things. Go to Preferences > Import and deactivate the option for hardware decoding acceleration. Then go to Edit > Purge > All Memory and Disk Cache. Restart After EFfects and try again.
Also could be interesting if you try to deactivate GPU acceleration under File > Project Settings > Video Rendering and Effects tab. Change the processing method to Mercury software only.
You are trying to use variable frame rate highly compressed MPEG video. It would help if you tried transcoding the footage to a frame-based production format. The Adobe Media Encoder or Handbrake can do the job. Just be sure that you don't render another highly compressed MP4 file.
It would help if you spent some time studying video standards and compression formats.