Attempting to export a MetaHuman from UE4.26.1 (100.5.126 connector) to Omniverse works great for all geometry except the face mesh, which ends up being an invalid mesh. Same results with either character in the publicly available sample project (BP_metahuman_001 and BP_metahuman_004).
(Not sure if this is the best place to report issues like this. If not, please let me know where is.)