Not all music syncing from Windows 10 PC to iPhone 13

I cannot sync all my music from my PC to my iPhone and it is becoming incredibly frustrating. I am using the latest version of iTunes (12.13.6.1) for Windows. I do not have a subscription to Apple Music. I have several thousand songs from albums I have bought in the past, ripped from CDs I own, or other purchased from other sources. The files are all in either .m4a or .mp3 format (the majority are variable bit rate mp3 encoded).

My computer is "Authorized" for my account.

The Apple Account is the same on both the computer and the iPhone.

When I plug my phone in to the computer via USB, and iTunes deigns to recognize it (which doesn't always happen), I get a pop-up on the phone to "Trust this computer?", and I enter my phone pin to enable the trust.

When I click on the phone icon in iTunes, I can see my phone, with the charge, available storage etc.

Under Settings --> Music there is a check mark next to "Sync Music 7124 songs"

The radio button for "Entire music library" is selected.

There is a check mark next to Include videos.

The check box is empty next to Include voice memos.

When I click the Sync button at the bottom of the page, the notification section at the top goes through several steps (6 I believe) including backing up my iPhone, and syncing music (according to the messages that I see).

If I click on Music under the section "On My Device" I see 7168 items - 17.9 days and underneath a list of songs. This list appears to be complete, but would be impossible to validate by eye given its length. That said, I can see in this list the songs for the album "Ori and the blind forest" by Gareth Coker.

HOWEVER, when I open the Apple Music app on my phone (red icon with a music note) SOME of my music is there, but none of the songs from Ori and the blind forest. Searching for the Album, the Artist, or a song name do not find it.

Specifically selecting that album to sync and redoing the sync does nothing to change this fact. There are other albums that refuse to sync as well (Starbound is one I noticed) but I have no idea how many, and I'm tearing my hair out trying to find a way to force them to be transfered to my phone.

Any help would be appreciated.