As I've explained above that functionality has been replaced by CB Core Fields Ajax. It is capable of handling "Update On" for all field types and is tested working for backend and frontend. The functionality currently in CB Code Field and CB Query Field for "Update On" will be removed in their next major releases (e.g. CB Query Field 6.0.0).
With that said I have retested the existing implementation within CB Query Field in backend while logged in as a Super User and Administrator while editing a Super User, Registered, and Administrator user. In all cases it worked fine. This was with a query select using its update on against a text field. What type of field is "cb_vehicle_01_type"? Is it accessible in backend when editing the user as well? Is CB Query Field completely up to date with the latest build? There are some known fixed issues as shown below on our forge.
forge.joomlapolis.com/projects/cb-cbqueryfield/issues