Syncing to iPod

There was a time when I would add new music to iTunes(from different sources), and the song would show up on my iPod (still does), and the artwork would download, and any playlist I would create would download, as well. That has turned in to a sometime thing now. I just tried this today, several times, with different solutions, and absolutely nothing will add my new playlist. I'm at the point that I'm not sure it's fixable. New and improved, the new ystem is not.