why my rigidbody ball either stops or bounces up when going from one surface to the next?

I have a ball (the standard sphere in unity) with a rigidbody attached. I have two meshes with flat surfaces that are vertex snapped so i know they're lined up perfectly (I zoomed in as far as i could on the mesh without seeing any flaws in the joining points as well) but when the ball is rolling across these two meshes most of the time it either skips in the air and flys out of the camera view, slow down significantly, or bounces back as if an invisible wall is there.

The imported meshes are set to auto generate colliders from blender in the import settings and my rigidbody is set to no interpollation and discrete collision detection (changing these combinations didn't seem to yield different results either.

Is there anyone that knows what is going on here? could it be an error in how the automatically generated colliders are made?