I have the same problem with Ionic and Deezer, during sync. Since more than one week. It already appends the previous years. “unable to join Deezer server”, and so on…

Please, Deezer could you allow Fitbit application to connect to your API and/or interface ? At this time, my deezer licence on Ionic has expired (3 days in order to check the account) and I cannot listen the  music already downloaded on my watch.

I had the same issue and so did my friend. We both had success by disconnecting Deezer from the Fitbit and re-connecting it. You have to download your music to the watch all over again, but at least it worked after doing that. 

Hello HookyLife.

Thank you for your answer ! But sorry to disturb, how "discinnecting" Deezer from the Fitbit ? In Fitbit App, I'm not able to find the option, and not on the watch.