Apple Music stalls when playing to Airplay via WiFi under Big Sur

Ugh. Spoke too soon. Problem is NOT solved durably under 12.6. It worked once, for hours. Since then, failure mode is back to previous state: freezes after 1 to 3 songs. Sigh and sigh.

@JovonaP - thanks for your response and suggestions. I have rebooted my Mac and restarted Music several times. That has no effect. I did add a test user and sign that user into my Music account. That user works!

Here is a complete list of the symptoms I'm experiencing and the things I've tried so far:

Configuration: MacBook Air (M1, 2020); Big Sur (11.6); Apple Music (1.1.6.37); WiFi connection to Sonos system.

• During playback from Apple Music via Wifi to speakers:
  • Playback “stalls” after 2-4 songs, usually at the end of a song.
  • After 2 or 3 songs, music playback status window inaccurate: doesn’t show progress on playing song; doesn’t reflect song being played; Command-L does not highlight song being played correctly; after next song, stalls out; playback status window still shows song preceding the last one played, with “playing” animation going - progress at 0:00. Those 2 songs not reflected in “History” listing.
  • iOS Remotes display incorrect information (don’t correctly track songs being played or having been played; don’t accurately track song playback progress)
  • Hitting “skip” on remote will cause an already-played song to play again
  • Hitting “skip” on Mac will re-start playing at next song in the queue, after which it will “stall” again
  • This happens with smart playlists and static playlists and just playing "songs"; with shuffled and sequential playback;
  • This happens with music that is downloaded to my Mac or that is being streamed (that is, streaming does not change behavior)
  • Happens with Home Sharing on or off
  • Remote behavior happens with Remotes using Home Sharing or paired with Apple Music
• Playback using Bluetooth speakers or Computer speakers works JUST FINE
  • Even if initiated after “stall” behavior, with just a change in output destination (from AirPlay WiFi to AirPlay BT).
• Playing music from iOS devices via WiFi works JUST FINE
• Monitoring playback from iOS devices on iOS SONOS app works JUST FINE (that is, SONOS iOS apps work fine)
• Monitoring playback from iOS devices on MacOS SONOS app works JUST FINE (that is, SONOS MacOS app works fine).
• Signing out of Apple Music and signing back in relieved the symptom for ONE session. Subsequently, stalling resumes.
• Created a test user and signed that user into my Apple Music account. This user plays JUST FINE with the downloaded library information.
  • Makes me think that the solution might be to delete and re-create my music library. I would like to be able to keep my playlists, though; could use some wisdom from the Community on this, if it’s the right next step to take.
  • The "test user" library shows 18905 items and 156.92GB
  • My library (the one that doesn't work anymore) shows 18975 items and 170.81GB
  • Not clear how to identify the 70 items that are different between the two libraries, though.

Thanks in advance for any suggestions you might have about next steps I can take to get this working. Ideally, I would be able to preserve my various playlists (smart and static).

No such luck; 12.1 did not solve the issue. 😢