how to download itunes library to ipod touch

Use iTunes to sync your iPhone, iPad, or iPod with your computer - https://support.apple.com/en-us/HT210612

I have an interesting problem I have not previously experienced. I am running Apple Music on an M1 Mac mini running Monterey 12.1. it hosts my media libraries. Everything works just fine—within the limits of Music, which I admit frustrates me regularly; I miss our old iTunes—but I have a new iPod Touch that I want to manually sync music to for one of my cars. I've done this several times before with zero problems. But not today. For some reason, in the iPod touch sync window, I can only see my TV shows and Movies (but clearly this is based on an old library listing, because my most recent movie and TV additions do not appear in the list), but cannot see my music, books, or audiobooks at all; those tabs are empty. Interestingly, I can see a list of playlists but, like the movies and TV shows, it is an old list. I've tried moving my iTunes Media folder to another drive, resetting my Files location in Music preferences, etc. But no matter what, iPod Sync will not see my current music (or any other) files. Is there some way to clean out all the old Library cruft and force Music to start all over again? TIA and Happy New Year!