@Diarmuid Collins in the screen that you showed, click in the search box. A menu will appear and you can select "public room". It will show you all rooms with "announcements" and "general" having the "view"! buttons checked and all the others having it cleared. Click on the button for "analog-design", for example, and you will be back at the screen you showed but you will now see three rooms. You can repeat the whole awkward process to add even more rooms to your list