If the Texts tab should be left as it is in the standard, then why do you cache it but make it invisible?
Do you have any required fields in the cached tabs? If yes, this may interfere with the tab caching; that could be the reason why caching fails as indicated by the red tab caching indicator. In this case, the consequence can also be that fields that were moved from other tabs don't show up.
More detailed screen shots of your flavor would help, along with some explanations.