Why isn't the Desktop App even trying to sync playlists?

[WPCentral Question]

I have a Lumia 1520 and my main WS for syncing my phone is Windows 7. The Windows Phone Desktop App often doesn't even try to sync the playlists any more. I've found I generally need to manually delete them out of the Music App on the phone, and then go into a hidden folder on the phone itself (not the SD card!) called Playlists and delete out a bunch of things which, before the delete, are named after the playlists, and after the delete just get called "local disk object". Even then it's not guaranteed - often the phone app won't even check to see if the playlists are there and doesn't even try to sync them.

This wasn't a problem before the 8.1 update. What the heck is going on?