Custom music disc titles do not work in realm

I have replaced some music discs in a resource pack.
I have edited en_US.lang, en_GB.lang and sv_SE.lang with the new "artist - title" information in this resource pack aswell.

When I use the resource pack on my own superflat creative testing world, the music plays as expected and the text that pops up is correct as expected.
However when I play the discs on my realm world, the text is reverted to what the original disc was, but the music file plays just fine.

This is a very minor issue I understand, it just boggles my mind why it works in one instance and only half works in another.