When I'm playing from my daily mix on Spotify, whilst open on the app, and I hear a song I like, I can press the heart button and it adds it to my songs automatically so I can listen to it later. However, if I go on another app, eg Google Chrome, whilst I have my daily mix playing in the background, and I hear a song I like, I press the heart button. But, this does not save the track to my songs, so after an hour or two of listening I could never hear the songs that I liked, as they had never saved. This annoyed me. I am fairly certain this is a bug, due to the fact that on the help pages it says pressing the heart button saves the track to your songs in your library; evidently, they have not done so.