Adding Track to Playlist

[Snouggin98]

I'm running the Spotify app on my iPad, iOS 10.3.3, the latest version. I've noticed, starting a few Spotify app iterations ago, that with some regularity when I go to add a track to a playlist from a radio station or playlist (Now Hear This, Today's Hits, etc.) I click on the playlist to add and nothing happens. No error, no confirmation... nothing. Sometimes I can skip tracks and then add other tracks, but if I return to the track, I cannot add it after playing other songs. I've also tried adding to different playlists, without success. Any idea why this inability to add to playlists is occurring? Thank you.