I am running the latest v18.104.22.168 on WP8.1
Today, while listening to Radio, I gave "Thumbs Up" to a bunch of songs which showed messgae "Improving your feed. Adding song to 'Liked From Radio' Playlist".
Later on, when I went to check, The playlist was absolutely as-it-is. Not a single song had been added.
I tried a dry run to see if it was an one off issue and found that songs were indeed not being added to playlist, although, starring a song is working.
Is this a bug?
For how long are WP users supposed to suffer?