I use Spotify premium with my Facebook and I've tried to link my account to PlayStation Spotify app. Initially it linked and I had a lot of fun, but next few days, it asked me to link the profile again and I couldnt do it.
The error says that my Spotify account is linked to other PS4 account. I've called PlayStation customer service but they are saying that I need to ask Spotify because my account is not link in My PSN. It must be Spotify issue.