I've just realized that although my songs are listed under the 'Favorites' section under the 'Suggested' tab in my Music library, the songs aren't actually favorited (since the heart is not red): When I click the red heart and then refresh the page, the heart turns back from red to grey for that same song.  I tested this through the web interface. The same thing happens when I favorite a song on the 'Songs' tab. See attached for a debug log on my server embyserver.txt