I added a song to a playlist then the playlist disappeared

I downloaded a song, then added it to a created playlist of mine, then the entire playlist disappeared. No matter what I do I can't get the playlist to come back and stay. Signing out of the account and signing back in doesn't work, uninstalling/reinstalling music app doesn't work. Closing iTunes, restarting computer doesn't work. Syncing iCloud library doesn't work. The playlist does come back at times but all music within it is greyed out/unsynced. Then it disappears again. This is one of my favorite playlists. Please advise how to fix.