Doesn't work for me unfortunately. When I press add to playlist a window appears to select a playlist, but none are listed, only Starred, but adding to that didn't solve the problem. In fact it made things worse as there seems to be no way of removing songs from that list!
I'm having the same problem and given that this appears to be an issue that a lot of people are having, you'd think Spotify would address it. This help forum is insanely confusing given when you google the problem dozens of instances of the exact same problem appear and literally none of them seem to tell how to fix it, yet they're all closed. One "solution" is literally a link to a post from 2014 about a bug which, is not a solution and is apparently still not fixed. I'm also in a trial period and this doesn't give me a lot of confidence.
This is ridiculous and cant believe spotify hasnt fixed this issue. I am experiencing this error on both my Samsung and LG smart TV. the problem has persisted for almost 2 months now and without a solution in sight, I am thinking about making the switch to apple music. Ive been a subscriber for almost 3 years now but this complete lack of knowlege of a problem or knowledge of any solution to this problem is not how a business of this caliber should be handling this. You may have lost a subscriber today, Spotify.