The "Add to Playlist" button on my Roku has not worked for a long time. The gear icon just spins and you have to back out.
When I first starting using Spotify on my Roku all of the options worked flawlessly. I have removed the channel, reinstalled it but to no avail. I have contacted Roku support but no help. I'm not sure whose court the ball is in, Spotify or Roku. I miss it a lot.