Update from SongShift here:
Update: October 21, 2020
With the release of SongShift v5.1.3, you will again be able to transfer playlists from Spotify to another service. The only caveat is, you have to have created the playlist yourself, or the playlist must be collaborative and followed by you.
Curated playlists created by Spotify are not eligible for transfer.
We are incredibly grateful to Spotify for updating its Developer TOS to allow these transfers. We're excited to continue to provide you a great music transfer experience.