Mesh brigthness changes depending on camera angle

Hi to everyone!

The procedural meshes that I’ve generated change intensity depending on the camera angle and I don’t know why. You can see it in the attached image: if I look up the floor becames darker, if I look down it becames brigther. I’d like to avoid this effect. I have already searched online but what I have found wasn’t able to help me. Any ideas? Thank you!

Does this also happen in the game view?

If not, try enabling the lighting in the scene:
When lighting is disabled in the scene view, Unity lights the scene with a directional light that is always aligned with the camera, which is why the effect occurs.