Sorry to revive this almost two month old thread, but the server is acting wonky again. I have attached two screenshots, one showing the state of the server at the end of a match. The server is full and DLC is still not activated. The second screenshot shows the server after starting the new match with about 50-55 players, and DLC is still disabled.
I have also noticed that in the evenings (EST), the server will revert to vanilla maps even if DLC was previously enabled for multiple rounds beforehand and will not re-enable DLC even if it is full. In any event, the DLC toggle is not working properly all of the time, only sporadically. It might not be a bad idea to perhaps permanently enable DLC, since there will be fewer players interested if to them, it appears to just be another vanilla maps server.