I’ve just come across an issue with favoriting tracks on the Roon iPhone app.
It seems that you cannot favorite a track unless the entire album is in your library - even if the track itself is in your library.
I’m listening to a playlist that I copied over from Tidal and created an editable copy of in my Roon library. On desktop, all of the tracks from that playlist appear under the “My Tracks” view and I can click the heart icon to favorite any of them. But on mobile, the heart icon will not appear in any view (when clicking the three dots on either of the now playing view, the track listing on the album view or My Tracks view, or the playlist itself).
However, if I add the entire album to my library (remember, the track is in my library), the track is now favoritable (though I still have to go to the album view to do so - I can’t favorite the track directly from Now Playing which seems silly).
It feels like like pretty basic functionality to be able to add AND favorite any track from Now Playing if the track is already in your library - when listening to a playlist or Roon Radio and thinking “hey, I like this!”