2D Polygon Collider Ball with bounce material not stay completely still

I'm trying to make a 2d bouncing bal. I have to put the polygon collider because if I put the circular one the ball takes a long time to stay still on flat surfaces. Dragging and releasing force is applied to the ball, the ball then bounces across the scenery until it is still. However, it does not stay completely still since it does not stop eternally moving by millimeters. I can't check then when the ball is completely still because it not stop moving! (If i take out the bounce material from the ball this situation never happens, that's because I think is the bounce material). Here is an example (sorry the quality): https://imgur.com/a/CIpCLFt