This may sound unorthodox but try rendering the seemingly faulty .obj import and see if the result is messed up too. Sometimes some hardware can give off messy results on imports but they look as they’re supposed to on final renders. You’ve got nothing to lose no?
already tried rendering this faulty OBJ file… render came out as this only no change… i am sure there’s some problem in exporter.
Why don’t you export directly off of SU instead of using a tool though?
If you want to learn a way how to repair that imported object in Blender
Otherwise, you can use the TIG - OBJ Exporter plugin and the OBJ model exported from SketchUp will look ok after you import it into Blender
