The in-game music stops working after you disconnect (i.e. manually disconnect or crash) and reconnect to a game. The only music that plays afterward are small things such as the respawn sound effect.

To Reproduce:
  1. Join a match.
  2. Disconnect from the match at any point throughout it.
  3. Reconnect to the match.

Music no longer plays for the rest of the game until you join a new match.

Music should play during the rest of the match after reconnecting, just as it does when joining a new game.

It's no fun playing a silent match with no music if you have to reconnect