We ran into this
DVC vs. hotel issue also at Saratoga Springs.
We are a party of five and one of our kids did not make it on the reservation. Saratoga Springs could not add a fifth person to the reservation because occupancy for the 1BR was four on the hotel side. DVC allows five, but it had to be done on the DVC side.
Once we were checked in, the cast members in the lobby could not add a fifth person.
Thus, that lucky fifth person would have issues if using their magic band for early entry or to open the room door.
This happened a couple of years ago, but I would be leery if there is a fix for some of these hotel vs. DVC issues.
My advice is to get everyone on the reservation before you make it to the resort.