Why isn’t my Apple Music syncing to my iPhone?

Like many others, when I cancelled my subscription to Apple Music I lost most of the music I had loaded from CDs, etc. Not all, but most. I resubscribed in an effort to recover what had been taken from me and it worked? On my Mac - my phone still doesn't know that. Except that my phone had lost all my music. Now it does have the limited amount that never completely went away on my Mac, but it doesn't have all of it. I've tried resyncing the phone and the Mac. What is going on?

[Re-Titled by Moderator]