Having trouble with normal(?) information from Maya to Unreal

I am trying to take a scene from maya 2017 (with fbx) into unreal. I didn’t add any normals in Maya or in Unreal (adding a completely flat Normal Map to the Material in Unreal changes nothing).
As you can see on the picture, there is an ugly transision fron the walls to the curve. I don’t want that. I just want a not visable transition over te objects.
Can you help me?
Thanks for anwears :slight_smile:

Make sure the Vertices are shared and in the same Object and make sure the faces have the same Smoothing Group.