Hi @egburley
Welcome to the Sonos Community!
It sounds like you need to re-create your "iTunes Music Library.xml" or "iTunes Library.xml" file, which stores your playlists. Apple Music no longer creates this file automatically, as iTunes used to - you can see this page on how to do so. Once done, re-index from within Sonos.
If this doesn’t work or you’re not sure how to do it, I recommend you get in touch with our technical support team who have tools at their disposal that will allow them to give you advice specific to your Sonos system and what it reports - they’ll also be able to start a remote session on your computer in order to fix it for you. For this reason, I recommend a phone call.
I hope this helps.
I had a similar issue on Android based on the November update - everthting was there from Apple Music but the playlists were all of a sudden gone. I stumbled on a solution by playing directly on Bluetooth from the Apple Music App and then going into Sonos. It appears to have relinked by having both open - hopefully it sticks.