Good afternoon, please tell me, when importing an animated object, the object itself becomes small at startup, that is, in the Unity scene, the size of the object changes and at startup the size becomes small or becomes the original size. And if you uncheck the animation of the object, then the object changes the size to what I want.
Check the scale of your imported object. Weird things always happen if the scale is something weird.
For such a simple object i would anyways recommend you to animate it directly in unity.
In case you imported it from blender hit Object-Apply-AllTransforms.
Perhaps try something in the sprite editor. I’m not sure if it will be there in 3D - I’ve been working on 2D for the past few weeks.