No music on Android, other sounds are there

It has been months now that I have this odd problem on Android: my game has all the sounds playing expect for the music.
I’m 100% sure that it isn’t a device problem since this week I changed phone and the problem is still there.
I already tried to uninstall and reinstall the game app but the situation is unchanged.
Steps to reproduce the problem:

  1. install the game
  2. first launch, music is there but the game is set on my device language so I change it English (UK)
  3. restart the app after the extra resources download and the music is gone