If I add a Game World Music Manager to a custom Ball Race map, enable “Use Built In Music”, and try to play the map, the built-in music that I chose doesn’t play.
In playtest mode it’ll always default to the GLXY music (even if that’s not the song I selected), and after finishing a bonus round, music stops playing entirely. When playing an upload of the map, there’s no music at all outside of bonus rounds.
Notes / Media
Game World Music Manager’s settings: