Regarding that normals issue. Which “Normal Import Method” did you choose at UE4 import? There was some change a few months ago and as far I remember “Compute Normals” with “Mikk Tspace” as the “Normal Generation Method” seems to be the default import setting now. Usually I get very bad results with “Mikk Tspace” while it works well if choose “Built in” instead or if I don’t compute them at import at all but choose “Import Normals and Tangents” at UE4 import instead.