Hi JGinYHZ,
What is happening when you try to download to Apple Music?
Your Apple One subscription should include your Apple Music subscription, and none of the functions of the Music app are supposed to change. Is Apple Music not working at all?
Try closing the Music app and restarting your iPhone if you haven't already:
Close an app on your iPhone or iPod touch
Restart your iPhone
Here is the process to download things into the Apple Music app:
1. Open the Apple Music app.
2. Touch and hold a song, album, or playlist that you want to add to your library.
3. Tap Download.
Add and download music from Apple Music
Make sure the tracks appear under downloaded and indicate they're downloaded.
Let us know if that helps.
Thanks for using the Apple Support Communities.