After much trails and tribulations on my part, here are a couple of things.
If you have icloud music library, your own music, purchased music and Apple music, things get messy when you upgrade.
To sync your own and purchased music to your new phone, icloud music library must be turned off. Your phone will not sync music while icloud library is enabled.
If you have downloaded apple music for offline listening, and you upgrade your phone, say goodby to your downloads. Apple does not allow that offline content to be backed up and synced to your new device. The content will show as part of your icloud library, but you will need to redownload if you want offline access to the tunes.
If you have icloud music library, your own music, purchased music and Apple music, things get messy when you upgrade.
To sync your own and purchased music to your new phone, icloud music library must be turned off. Your phone will not sync music while icloud library is enabled.
If you have downloaded apple music for offline listening, and you upgrade your phone, say goodby to your downloads. Apple does not allow that offline content to be backed up and synced to your new device. The content will show as part of your icloud library, but you will need to redownload if you want offline access to the tunes.