@dostovel I took a look at the file and I can’t figure out what’s going on with that piece. My last resort would be to export that piece as an OBJ and re-import into the scene, deleting the problematic original. I use this technique to clear any blender-specific data from the mesh; refresh it if you will.
Very odd though. Yeah I would see where / if it’s noticeable in the renders. But we can re-render if needed.