If it’s an instance maybe try unlinking it? It could be reacting strangely on export.
Try to open up a fresh scene in blender and importing the FBX itself and see how the normals look in the exported file, not on the original scene.
If it’s an instance maybe try unlinking it? It could be reacting strangely on export.
Try to open up a fresh scene in blender and importing the FBX itself and see how the normals look in the exported file, not on the original scene.