giving any other info you think might be relevant would be helpful. heres some troubleshooting steps i can give you without knowing anything:
did you close and reopen the game?
did you try unsubscribing and resubscribing?
do you have mods enabled?
do you have soundtrack menu installed? (install the original mod if you don't want to switch between multiple soundtracks, you can find it at the top of the description)

hi im a bit late but the music doesnt seem to change for me? Do i have to somehow change the default soundtrack myself? thanks

Insisting for kether 3!

awh keter battle 3 isn't in this

Обожаю малкух битву 1, спасибо большое

thank you very very much

thank you!

I love the soundtrack so thank you

thank you

love mili :)

@Krakkip:
Fixed. I didn't read the example music.xml files hard enough, oops. Please let me know if this happens with any other songs!

@Krakkip:
Thank you for letting me know. This is happening for me, too, and no matter what I do I can't fix it. I'll have to ask around.

Oh nice didn't think this would work right with the soundtrack mod. Although for me the Womb soundtrack does not play.

Much appreciated