Wrong materials display in Occulus Quest VR


I have run across a weird problem with materials in VR.

I have built an architectural model in C4D and imported via Datasmith into UE4.26.1. In the editor the materials are displaying pretty much as they do in C4D, even those assigned to individual polys via selection tags.

However, when I launch to my Oculus Quest 2 and view in headset, almost all the materials have been switched out for a completely different one.

Any insight as to why this might be is greatly appreciated,