It looks like a problem with overlapping polygons or incorrect mesh normals.
Do you still have a version of this scene with the black counter? If so, could you share the scene link with us? If you could share the input FBX file as well, thatβd be great too. (If the scene isnβt public please send the the link/FBX via PM or to support@shapespark.com).
I have experienced a very similar issue before - In my case, when the Double sided material is ticked the back face is always displayed as black. To resolve this I simply had to reverse/flip the faces that were an issue and reload the model back into Shapespark.