Okay so I made a video to demonstrate the problem I'm having. When I upload the ,obj version, and test the normal map on the model, it displays correctly, everything looks great!
When i try to upload and test the normal map on the FBX version, I cant even describe whats wrong with it, it's not a problem with the normal, i think, it honestly looks like the smooth shading is inverted. I'm including every file, the .blend file and both the .obj and the .fbx animated versions. This problem keeps coming up for me with sketchfab over and over and over and I can never find a solution. If i load the .fbx into any other software, 3d programs, substance paint, ect, it works fine. Its killing me that i cant solve this. I cant even find instances of other people having this problem. I keep having to abandon projects because of this.
heres the video https://www.youtube.com/watch?v=UX0DSyGKh84
heres the files i was working with