To leave a lobby I need like 3 seconds instead of half a second.
The lobby was locked and the game was counting down from 5 to 2 or something like that (until the lobby window was closed).
Like my character left the lobby right away but I could still see a lobby with one spot being free for about 3 seconds.
(talking about arcade lobbies mostly and I never ever had this problem in all of the 6 years of Sc2 - only after the latest patch.)
Edit: correction: It’s actually full 5 seconds until the lobby window disappears!