When joining any map you get the "Welcome to " sound.
BUT, if you backfill in a match then there is no sound. Often I’m tabbed out while queuing. This results in me not knowing I get into a backfill match until the afk timer starts counting down.
I don’t think this is a bug, I think its designed that way.
The “welcome” sound only plays at the very beginning of the match. If you go into a replay, it will even play the sound at the beginning. So basically, the “welcome” sound is server side and not client side, which is why it doesn’t play.
Also I think it’d add salt to the wound of backfilling into Paris and having athena say “welcome to paris :D”