I’m running the latest 4.2 with KDE. The audio worked fine initially. Not anymore. Something has changed.
Audio keeps muting itself. To get it working again, I have to switch the audio profile using the audio applet, then switch back. It will work for a few minutes, then mutes itself again.
It’s not perfect, as I can boot up and if I don’t plug in headphones initially for some reason it fails to register that there is an audio device and needs to be restarted. It fixed the issue for me though and I have had no repeats of the problem aside from what I just described, which relative to the original issue is minor.
Clearly this is a bug with 4.2
I was also running KDE so maybe that is the common thread?