It would be helpful if you could include a link to the project. If you are trying to use and animated sprite as a child of a 2D screen, you will find that 2D screens only support objects with the ‘element’ component.
Unfortunately, the element component does not support animated sprites. Here is a post outlining alternatives for a 2D screen:
Since you said this is not on a 2D screen, I’m not too sure what it could be without seeing the project.