Question: Why does it say the hotel is sold out?
If you are reading this before October 15, 2019, chances are you have selected a night where just one of the room blocks is full. When that happens, it tends to kick out your entire reservation attempt when this happens.
REMEMBER, THE DESIGNER AWARDS GALA IS WEDNESDAY, JANUARY 29TH. Unless it is your intention to stay over in St. Louis for extra time to site see or otherwise, there is no reason for you to reserve a room on the night of January 30th.
If you are reading this AFTER October 15, 2019, there is a possibility that our entire room block is filled. If that is the case, then you will either need to pay the full rate of the hotel (which can range from $175 to $295 per night) or find a different hotel to stay in.