3DS Max fbx model losing UV maps when splitting up meshes

I have an fbx model that had some large meshes with more than one material assigned (multi-material). In unity it only displays the first material in the multi-material. My proposed solution was to just split the mesh up so that I could have one unique material per mesh. But, when I split the mesh up, the UV mapping is lost in Unity. It still looks/renders perfectly fine in 3DSMax but not in Unity. Is there some extra processing I need to do. I do not really want UV map these again as they are fairly complex.

My solution was to go into the 3ds Channel info dialog and move the mapping data to the appropriate map channel (1) and reapply material. Because it was originally a multi material the maps were distributed over 30+ channels for some objects. It’s ridiculous that I have to dig that deep in 3ds to find the uv mapping index. All is well now…