New to Oculus and we just discovered this too! Purchased and played Billie Ellish and Interscope Mixtape in my (primary) admin account yesterday and my son went to play in his (secondary) account today only to find he could not use those packs without buying!! Its just ridiculous that in an already shared app like beat saber any add on such as music packs aren't available to all accounts on the same headset!! Extremely disappointing!!!