@mix This is the same .rfa from this post, right? Element.geometry cad Are you using it in a different project? Also, when you created the nested family as Revit geometry, did you explode the CAD or did you model it? Strange issue 
@mix This is the same .rfa from this post, right? Element.geometry cad Are you using it in a different project? Also, when you created the nested family as Revit geometry, did you explode the CAD or did you model it? Strange issue