I think the lobby bug is rearing its head again. The menus are there but they are invisible. When I joined in @Bos5k games the join button wasn’t there but if clicked where it should be, I was added.
I’ve had some success in the past by selecting an item from the menu while it’s invisible which causes it to redraw.
You can also try going into a battle (tutorial or spectate are quickest) then going back into the lobby