I’ve tried every single import method for normals and it doesnt seem to change anything at all.
It is definately not the issue with my .fbx file since the hard shaded edges are still there when i import it anywhere else I tried (Blender, Substance painter).
for me it was because in the unreal import dialog box, i had at the “Import normals” (open advanced section) option set to “compute normals” which will create new normals for the mesh. set it to “import normals” and for me that solved it.