Model broken after FBX export to Blender and back

Exporting to FBX the object on the left, then importing and without any changes exporting from Blender gives the result on the right. Any tip on why it is happening?

Is there a term for this issue I could look up to understand how to fix it?

Thanks

im not sure tbh, but it looks like normals are flipped.

this is a popular vid that inverts em. deos it help?