It is very strange that you are unable to update the station global variable.
Have you tried stepping through your TestStand and LabVIEW code to make sure that the variable is being updated? By walking through the code you might be able to find if the variable is updated or not.
Also, how are you checking that the variable is being changed in both of your user interfaces? Are you checking in the same way for both interfaces?
Thanks,
Santiago D
National Instruments