Animation Frame Jumping

DarthD

https://youtu.be/-jkJxNRPNCo

I had this issue a long time ago, certain aniblocks that once worked fine started doing this then the problem went away. Now it seems to be comming back. This time, however, the animation worked fine in this scene, it was saved many times as I worked on it and had no problems. One day when I opened the scene, the character was frame jumping. I can create a new scene and load the aniblock and she does not frame jump. Does anyone know what causes this?