The problem is not with go to object. It lies with how FileMaker processes the "triggering event" when OnObjectExit is triggered. FileMaker performs the script specified for the trigger, then goes ahead and processes the triggering event. In this case, that event then puts the focus into the next field in your tab order even if that is not where the script tried to put it with go to object.
The solution is to use Exit Script [False] to terminate your script after using either go to field or go to object to put the focus in the desired field. This step keeps FileMaker from processing that "triggering event".
For more on this issue and which triggers process the triggering event before the script and which process the event after the script, see: Setting up script triggers in FileMaker help.
That did the trick!
Thanks much, b