Nobody in our group is getting invites from the host since the update.
Manually joining from the friends list works, but only once. So each game you either need to host your own private game or restart the game entirely. Which causes the friends list to update and display “Join Game” again.
Something really got broken with the online services in this update.
Still broken on 17734.
Still broken on 18067.
Still broken on 18820.
Seems to be fixed for now in 184.108.40.20694.