when you import to UE4 what setting are you using for the normals?, I have had some similar results when using “calculate normals”, if you haven’t already you could try changing it to “import normals”, might help might not:p.
when you import to UE4 what setting are you using for the normals?, I have had some similar results when using “calculate normals”, if you haven’t already you could try changing it to “import normals”, might help might not:p.