I’ve exported the MetaHuman face mesh along with the LODs into Blender to do some editing. While still in Blender, all the material slots are available on the mesh (after processing the FBX with FBX Converter). However, after reimporting the mesh back into UE5 the material slots for the LODs seem to have been removed (not the regular material slots - only LOD slots). This completely breaks the MetaHuman LOD system. I’ve verified that it is Unreal that is the culprit by reimporting the edited FBX into Blender, and sure enough all the slots are there. Could it be that UE5 deletes material slots that are not assigned to any vertices and fails to account for slots on LOD meshes?