when will Music Assistant's Spotify integration be fixed at the librespot streaming layer. The OAuth login shows "authenticated" fine, but under the hood librespot rejects every track with INVALID_CREDENTIALS.

It’s my understanding that this is causing the problem that music assistant is not working Especially with respect to Spotify although Spotify Connect works. Any idea when this issue will be resolved

You should report this here
https://github.com/music-assistant/support/issues

Or, just check for existing issues and leave a thumbs up Spotify playback fails with FaultyRequest(INVALID_CREDENTIALS) despite successful OAuth login · Issue #6051 · music-assistant/support · GitHub