I have not had success moving a dining reservation on the day of the reservation unless I call the dining line directly. When you click to change it in
MDE, there is a notice that gives me a phone number to call for help. I overheard some cast members talking to visitors and they said that all the CMs are aware of the boarding group situation so if people are outside of their windows for FPs to just let the CM know when you scan in...the same goes for dining reservations but if you miss one you need to speak to Guest Services or call the dining line. Here is a tip I was given today: If you happen to experience downtime at RotR and receive a recovery FP (Like so many of us did today) make sure to verify with a CM before you tap in at your “late” FP location because the recovery FP may be erroneously used by the system.