A TEB is an interactive object, you could have used its Success action to show the hidden text caption with a simple or an advanced action. I think you have made this too complicated and probably have a logical bug somewhere. The Success action for the TEB, will be executed even if the TEB is not validated. Have a look at events that can trigger an (advanced) action:
http://blog.lilybiri.com/events-and-advanced-actions
Lilybiri