How do I make my entity not "climbable"?

Your wall isn’t really a wall either. It consists of different layers that are not equal to each other. Because of this you create the opportunity to climb on it. This would work the same in real life.

You can improve this by equalizing the parts or making it one whole (a parent entity with the collision and rigidbody component and some children with a render component).

Okay, I also just thought of another way to make it not climbable, adding a tilting out. you cant climb a tilted wall tilted toward you

Your sensor length is to long, so even without a wall you can climb. In your case a value of 2 should be fine.

Ok