I attempted to join a lobby through the lobby browser but changed my mind as I was joining, so I quit to the main menu. (I remember that the game used to prompt to press F10 to cancel, but there is no prompt now and pressing F10 doesn’t work.)
After loading back into the keep, I joined another game through the lobby browser. What’s weird is I can see the chat messages of the first lobby I tried to join even if I am already playing the game on another lobby.
As per the first lobby players’ chat messages, it appears that they are unable to finish because apparently, I am still joining their lobby. As mentioned here by one of the friendlier members of the fine Vermintide community:
I’ve been able to finish my match and they still haven’t finished theirs:
This has been a bug even before WoM Patch 2.0. It has been reported before here: Combined Lobbies Bug / Crash on start up