Sheep with buggy animation

Before I begin, I would like to make it clear that any errors in my language are because I am not fluent in English. It's very simple to bug every time a sheep tries to eat grass it bugs and stays with the animation of eating forever, but it can still eat, walk and do everything but it doesn't leave that position. I recorded a video showing (I'm speaking Portuguese because I didn't know that the site only accepts English but it's just ignored )