Apple music sync issues

I switched to apple music for convenience a few months ago and am trying to get my main playlist to work correctly. I manage my music on my windows desktop and listen on the go with my iphone.

I am running into an issue where a playlist that I can clearly see on my desktop is how I want it.

But I can't manually sync the playlist to my iphone so it only shows an un-updated version of the playlist on my iphone. I am having some sort of issue, I think with sync library or apple music, but I can't figure out how to get this to work properly.

I've been combing everything I can online to figure out what exactly is going on but I can find nothing.

My itunes library is about 21,000 songs now so I am wondering if it is a storage issue, but I'm at a total loss, as I've read that apple music and sync library can handle up to 100,000 songs.

Clearly I'm doing something wrong, I just can't figure it out.

Desktop view of the playlist

View on Iphone

View if I right-click the playlist on desktop and hit "Show in apple music"

All the songs that I put in the playlist when i was on desktop are easily visible outside the playlist when i search for them on my iphone, but the playlist isn't updating.