Vincent AI - quality of the video drops

when using Vincent AI, the quality of the video drops significantly, while the first second is okay, the longer the video, the worse it gets. What could cause this issue? It looks like some kind of bitrate dropping issue. It actually happens with every AI, my 4 second videos are getting demolished by the end of them.

No idea without additional information. What is the resolution of the video before the edit and after the edit ?
Can you upload the input and output somewhere so we can check ?