Ive found a lot of similar problems but not my exact problem. At first I thought my uv maps werent working because a lot of my maps were outside the 0.1. But I retextured everything to fit and I imported into unreal and I was so happy that everything looked exactly like how I mapped it out. Until I realized that I forgot to select the skeleton on export and it was only a static mesh. So I re exported with the skeleton selected, then to my dispointment the UVs were all messed up… So it has to be something I am doing wrong and not the actual maps as they look perfect when I import as a static mesh I imagine that if the maps were the proble they would looked messed up no matter how I imported.
For anyone who comes across this similar problem, it would appear that I have fixed it. I triangulated the mesh before export, and unchecked triangulation from FBX export. If youre worried it will mess with your bind it wont. Binds calculate verts not faces. I realized that because you adjust binds based on verts. any how.