Something is really wrong with my physics(or code)

Hi,
It’s easier to read code you post here if you use the code tags:

I wonder if you need physics & colliders & stuff at all for a chess game? I think I’d be tempted to do it without physics.
If you do want physics, there’s a nice diagram here showing various options that can work nicely:

About your actual problem, I’m a bit confused by

GetComponent<MeshCollider>().transform.position = moverA;

It feels weird to me to be moving the position of a collider, but there’s no screenshots of your project so I’m not sure, maybe it’s fine.

Good luck!