Hi, I'm currently booked in a cat 4a on deck 10 on fantasy and keep checking to see if anything opens on deck 9. There are no other empty rooms in cat 4a. In doing so I noticed cat 4b shows up but when I go to see if there are any rooms there but when I try to assign a room it says GTY only. Why would this be? If you sign up for gty you have to get your category or above right?