"Mute when not focused" setting doesn't work until character select.
Not sure if this is intended or not, but it's really annoying. After launching the game, I always alt-tab to open Spotify or YouTube because the game takes 8 years to get to character select. During this time the music blasts full volume even though I have the game muted when not focused. As soon as I get to character select the music turns off when I alt-tab. Annoying feature/bug.