Music playlists missing

I have about a dozen playlists and something has happened where they have become corrupted. Specifically, the music itself is still in my library. But somehow about a half dozen of my playlists are missing most or all of the songs I put into them. Is there a file I can restore to fix this? I do TimeMachine back ups pretty regularly.

I noticed this the other day and have not been able to find a solution. But one thing is definitely clear, it was recent because about a week ago, my playlists were full intact. For what it is worth, when I go into Music > iTunes and look at the *.itdb files they are dated 2019. So I'm not sure what file I need to restore.

Only changes I can think of that has happened in the last couple weeks are:

1. I changed my AppleID email address associated with my existing AppleID (not to be confused with getting a new AppleID). So all the songs play just fine when I go to the album. And, the songs that are no longer in my playlists are both songs I purchased from the iTunes stores and songs that I ripped from a CD I own.
2. I recently purchased a new iPad Air that I sync my music with. So my music is on my iMac, my new iPad Air, and my iPhone. And the corrupted playlists are the same on all devices.

thx!