Do you think it may be something in the robot's programming? It sounds like you have a mistake in the program somewhere where the program assigns unsigned characters and their respective functions....
If not, (if you are talking about the white joysticks) there are plenty of teams (including us) who have decided not to use those joysticks, and have a few still sealed in their original boxes. I don't know if we are saving them to use later, though. If you request, I could be able to determine whether or not we can be able to send one to you. PM me if you are interested
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