First person camera movement can’t go backword

Hello,
i try to make a simple showroom and to navigate it in first person.
I set the collision material and it’s working fine, but…
While moving backward pressing “s”, the camera stop working an it’s stuck if i’ll watching down (below horizontal line).
I think it’s trying to move itself above the collision plane but it can’t do it and it’s blocking also the ability to move along the other axis.

When i move forward pressing “w” the camera it’s moving fine, i can watch up or down while moving without problems.

It’s really annoyng

Any advices on how to debug it?