Im having the same issue for the conference league.
Probably related but just want to be sure this is known
Additional: everytime I pause the match the hymne stops, but when I resume the game, the hymne also starts from the beginning
Edit: Even when the hymne has completely played and is finished, if I pause and resume the match, the hymne also starts again.
Edit2: Even if i disable the music in the "in game match settings" the hymne keeps playing.. My god this is annoying