My iPhone Music Playlists aren't syncing with my laptop

This is a fairly recent issue since the last update to my iPhone XS (version 18.4.1) - Basically what's happening is I regularly use my music library (all local copies - I don't have Apple Music synced up with any streaming) and do playlisting on the fly on my iPhone. What should typically happen is I will make up playlists on my iPhone, and then when I link it up to my laptop and it syncs up with any new music I've added to my collection, it will also sync up the Playlists back to my laptop, and I can sort them out and arrange them in the Apple Music application. What's happened now is that while the new tunes I've added to the laptop are showing up on the iPhone, none of the playlists I've created since the last time I synced are showing up on the laptop.

I've tried ejecting and re-plugging, re-hitting the "sync" button in Finder, looking for any software updates to the laptop or any firmware updates for the iPhone (none exist) and I can't find anything. I am using a 2017 MacBook Pro i7 with touchbar, running MacOS Big Sur (11.7.10).