Line separating slab and stair despite same material

[JamesBell]

Hi there,

There is a line separating this slab and stair despite them being made of the same material.

I have a stair above that is using the same graphic overrides with no issue.

[Mahmoud Qenawi]

Sometimes small deviation while modeling slab causes this so get assured that the slab is quite parallel to the stair also stair may need to be rotated slightly, i hope that fixes.