I have attached a GIF of shaking animation. Is this the issue you are having?
I am having the same issue. The frames are the same size and the image is at the same position. I also tried as a sprite sheet, there should not be any shake or cutting. This started happening a few days ago and does the same thing for any animation I make. The whole project I have been working on for about 8 months never had this issue. I have not changed anything in my workflow. Not sure why this started happening.