Spatial audio, turn off & return to traditional stereo

gillstory,

When disabling the feature were the steps below, and found in the article here completed? About Spatial Audio with Dolby Atmos in Apple Music - Apple Support

"Choose how to listen to Dolby Atmos on your Mac

1. Update your Mac to the latest version of macOS.
2. Open the Apple Music app.
3. In the menu bar, choose Music > Preferences.
4. Click the Playback tab. 
5. Choose Automatic, Always On, or Off."

If so, be sure to also check the streaming quality options. The guide here can assist: Change Playback preferences in Music on Mac

Regarding spatial audio this should only be an option when using AirPods or Beats Fit Pro with your Mac. Are you using any of these headsets? Listen with spatial audio for AirPods and Beats

Best.

Hello gillstory,

We understand that you're wanting Spatial Audio and Dolby Atmos to remain disabled in Apple Music, however it appears to be turning back on on its own. Is that right? Do you find this happens with certain songs or is it random? If you find it happens when a particular track is played, is it downloaded to your device or are you streaming? If downloaded, try deleting it and redownload to see if the same thing happens.

If you're looking to move back to a previous macOS you can do that, however you might miss out on the features and security provided by the more updated macOS versions. However, if you'd like to downgrade, the article below will help with the macOS switch.

How to get old versions of macOS - Apple Support

Best regards.