2D: Why are my Circle Colliders falling through Edge Colliders ??

Hi, I have a player sprite with a circle collider 2d at his feet. I have him standing on an edge collider 2d. The edge collider is part of a large moving tank that rolls around climbing over rocks and other colliders.

When the tank gets bumped around, the sprite sometimes falls through the edge collider and ends up on the ground next to the tank. there are no holes in the edge collider, its mostly a long flat piece. He isn’t standing anywhere near the end of the collider, he is definitely falling straight through.

Is there a setting or something that says never go through, no matter how hard it hits?

Thanks!

Answered in Comments. Thanks Pyrian and MrSoad