Welcome to CC and the Princess forum.
It has, for some, shown a charge and then comes back as 0, or it doesn’t charge the card.
However, the IT dept is changing the dining on the App and will be finished on June 17th. Now, this is supposed to be for the MDR and not SD Specialty dining. Also, if you’re referring to a July booking, it should not affect you. Because of updates, it could affect your booking it right now.
So, if it does charge you on the credit card, once OB the GS can credit it as refundable OBC. Or, you could just call the dine line on your cabin phone and book the SD reservations that you want. That’s what we do.
It does take a few days from when you add the package to reflect on the App. Try again. Or, use the website version of the App, cruise personalizer, dining.