Thanks for opening the ticket. However, the noted “fix” does not correct the issue, at least in my observation. I am testing using the Test function on the audio playback device in the KDE Audio Control Panel, FYI.
Clicking Test will not play audio, under any condition, whether I change the audio quality settings in the session control panel back and forth, or not. One further observation is that, if I toggle the Mute Server Audio setting off and on in the session control panel, the in-session volume (e.g. KDE’s volume of the audio output) returns to its original setting of ~15% volume. I always return it to 100%, however that does nothing. Perhaps volume setting updates are not being processed?