2D animation is trembling

Sorry if I’m writing to the wrong discussion.

Hello. What is the reason for twitching character animation move? In the Flipbook preview, everything is fine. In the game, the character feels “heavy”, as if he was trembling or flickering. This is best seen on the shoulder and face.
There is no such effect in a fully 2D project.
https://www.youtube.com/watch?v=j2u2…ature=youtu.be

UPD:
That only when character is move https://youtu.be/-vCWosNbZU0