iTunes not syncing all music to iPhone 17 Pro Max

I downloaded 3000+ songs some years ago from my iTunes on a PC running Windows 10 onto an original classic IPOD. Just got an iPhone 17 pro max and tried to sync my library to my new iPhone using ITUNES with a cable. Only two albums synced. iTunes recognizes the new iPhone but can seem to get any of the remaining songs/artists to sync to the new phone. I have a newer PC with windows 11 and another version of iTunes but have not tried to transfer anything onto that. Just want my 3000+ songs to transfer to my new iPhone for now. HELP!!