Navmeshagent can't avoid collisions

On Mech character i got navmeshagent set up with obstacle avoidance and capsule collider size of whole mesh. Its moving fine on flat ground but for some reason it can fit itself through small doors, which it shouldn’t.
Ground and building is one mesh with mesh collider and it working just fine in all other occasions.

thanks in advance)

So by poking around more find answer - in navMeshAgent create new Agent type - and there i can set dimensions of character and some other stuff, then bake new surface with new agent and its done)