Hi. I can't find the solution to this from other threads. I have these shading errors on faces whenever I apply a normal map. I use the same workflow for all my models - model low poly, export as FBX to Unfold3D, reimport as FBX with UVs set up, apply smoothing groups, export low poly, high poly, cage as FBX, bake in XNormal. I mirrored / re-attached the model, although so far I didn't get this issue.
Things I tried : reset smoothing groups, Normals Modifier - Unify Normals, Edit Normals Modifier - Reset Normals, Reset XForm, create a cube and attach glitched model to it. NOTE: face shading error appears with any normal map material applied!