I had an audio issue with v15b1, but can't figure out how it happened. Basically the audio stopped playing, even across projects. No green bars showed in the mixers in either the Edit or Fairlight tabs during playback. I changed my Win10 audio settings, switched between headphones and speakers, and checked every volume slider and mute button in DR. Uninstalled and reinstalled, but still no luck. Toggled the Preferences/SpeakerSetup settings from "use system" to "manual" and had no luck...until I toggled to Manual, selected a device, then selected same setting I used in Manual for the left and right stem outputs (not sure what that means). Then audio returned! Yay! Toggled back to "Use system settings" and audio continues as expected.
Sorry, I know that's not very helpful info, but still not sure how I turned off the audio to begin with, nor why toggling the speaker setup brought it back. I do have the log, if that would be interesting to you...