Auth Error Spotify Integration Music Assistant

Hello,

since Spotify authenticate the playback seperatly I am getting an error. Authenticate to Spotify itself is successful. But when I want to auth the playback via browser it wants to call this URL and the 404 pops up:
http://127.0.0.1:5588/login?code=

I have this redirect URL in Spotify:
https://my.home-assistant.io/redirect/oauth

Do you have any suggestions?

Thank you