I'm having similar issues for my June 23rd Wonder cruise.
Can we book MTD reservation times once we get on the ship? If I head straight to the dining room when I get on, will they have reservations open then?
Right now, I have one night booked at 7:30 and there are no other nights available to book. I'd prefer a 6:30 dining time every night and I was hoping I can just go to the dining room when we board to reserve it with them.