Qobuz - can't login

I own a Volumio Primo & I got a Volumio Superstar subscription and an active Qobuz Test Subscription. When I try to login via Volumio GUI by username or E-Mail plus password nothing happens. Volumio GUI just shows a progress bar (few seconds) and then the empty login Screen shows again. Password is 21 characters long, just lower/uperclass characters and some digits. No special chars in username. One special char (+) in E-Mail.

I’d like to use Qobuz via Volumio. What else can I do?

System-Version 2.703

Logfile:

[code] ___
/_ \ __
__ __ //\ \ __ __ ___ ___ /_\ ___
/\ /\ \ / __\\ \ \ /\ \/\ \ /' __ __\/\ \ / __\
\ \ _/ |/\ \L\ \
\ _\ \ _\ /\ /\ /\ \ \ /\ \L\
\ _
/ \ _//_\ _/\ _\ _\ _\ _\ _/
// // // // /////////___/

         Free Audiophile Linux Music Player - Version 2.0

      C 2015 Michelangelo Guarise - Volumio Team - Volumio.org

Volumio Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
volumio@volumioprimo:~$ journalctl -f
No journal files were found.
^C
volumio@volumioprimo:~$ sudo journalctl -f
– Logs begin at Sat 2020-02-15 12:10:59 UTC. –
Feb 15 12:21:55 volumioprimo volumio-streaming-daemon[1464]: Loading tidal configuration
Feb 15 12:21:55 volumioprimo volumio[904]: info: CoreCommandRouter::getUIConfigOnPlugin
Feb 15 12:23:01 volumioprimo volumio[904]: info: CALLMETHOD: music_service streaming_services saveQOBUZAccount [object Object]
Feb 15 12:23:01 volumioprimo volumio[904]: info: CoreCommandRouter::executeOnPlugin: streaming_services , saveQOBUZAccount
Feb 15 12:23:01 volumioprimo volumio-streaming-daemon[1464]: Login con Username + Password for service qobuz
Feb 15 12:23:02 volumioprimo volumio[904]: info: CoreCommandRouter::executeOnPlugin: my_music , getUIConfig
Feb 15 12:23:02 volumioprimo volumio[904]: info: CoreCommandRouter::getUIConfigOnPlugin
Feb 15 12:23:02 volumioprimo volumio-streaming-daemon[1464]: Loading tidal configuration
Feb 15 12:23:02 volumioprimo volumio[904]: info: CoreCommandRouter::getUIConfigOnPlugin

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