I have noticed on both my phone and tablet that sometimes when I press the heart icon for a song it won’t remain highlighted. The heart will light up momentarily then switch back to its unselected state. However if I go to the album the song shows a highlighted heart.
Also, on the Now Playing screen, touch responsiveness is very inconsistent. For example, pressing the microphone icon to bring up lyrics only works about 50% of the time. Same issue with the other icons (heart, repeat, 3 button option, etc.)?
The Alpha testers have made the developers aware of the heart issue. When you press the heart, it will flash on then off. In this case, the song actually has been favourited, you just cannot see it in this view.
Anyway, they are trying to determine what is causing this issue, but haven’t had much luck yet.
I don’t recall any responsiveness issues with tablets. It could be a problem with the phone apps, since the icons are so small. It can make them hard to hit.