Problem with meshes imported to UE4 from Cinema4D

Hi guys,
Total newbie here…I’m importing an interior arch scene to UE4 via datasmith from Cinema4D R21.
In the attached pic you can see that I have 2 sofas in c4d, both with the same phong tag, however, when imported into UE4 - one of the sofas looks bad…Any idea what’s causing this and how to correct it ?