Collision : Character tripping between perfectly aligned tiles of ground

Hello !
I'm making a kind of endless runner, with procedural ground generation.
Ground is 2x2 tiles meshes with box collider, player is animated mesh with a capsule collider.

When the player crosses the limit between two tiles, he has a little jump even tough they are perfectly aligned, like illustrated by following animation (only colliders are shown, two tiles + a step by step moving character) :

Do you know why it does this and how to make it work as intended ? (obviously I don't want the character to jump ^^)

Edit: I did try and replace the capsule collider by a box collider, the box collider just get stuck on the edge of the tile as if there was a step between.

 

put a physics material on iz, and give it a friction of 0

 

I tried that one with no success, sadly, on both the character and the ground. The little jump is still there.

 

This answer on another thread helped me !