If I save a new track, then add track to my offline playlist.
First, make a playlist called Offline and set the Download switch to Green. Then go to Songs under Your Music, click on one track and then hit ctrl+a. After that, go back to the Offline playlist and hit ctrl+v. If you apply this recipe, all your new saved songs will be copied to the Offline list and downloaded when you are online. Don't forget to hit the download switch on your other devices as well ;)