[ringwalt]

Google Play Music is the same, at least on iOS (well, the storage usage is accurate). It caches any song you listen to once or twice, until it eats up all free space. Then your only choice is to purge the entire cache, except for albums you've manually downloaded (which can only be set at an album granularity).

[joe5150]

Well with Apple Music you can't manually trigger a cache purge (to my knowledge) and of course you can't delete the Music app and reinstall it. Maybe toggling Apple Music or iCloud Music Library off/on would do it? But I tend to want to avoid ever changing iCloud-related settings on my phone once they appear to be working correctly, due to my experience of them just falling apart in the past.