202203 edit: some monstrosity called 'iCloud Music Library Sync' sucks up data usage to the tune of gigs/day if not disabled. Nice Apple, nice. Gave Apple Music another shot. Still can't Chromecast from an iPhone. App still gets 'confused' when Chromecasting from Android. And don't get me started on the family management. Yuck. I'll try again in 2023 I guess