We had no issue as a group dining on Apex. With linked bookings, they knew that we were together and planned our table accordingly. We started the cruise as a early seating but during the cruise, the ship turned into select only dining. Our ‘ select ‘ became a six o’clock booking each night and we just chose a different restaurant. Our group just moved as one, and table preference seemed to move with it.
I would suggest speaking with a Maitre D as soon as you board the ship. They are very accommodating. Another idea is to call Celebrity. I believe that they can prebook the select seating time for your group as well.