As an addition to this, when unplugged it doesn't properly revert to HDMI audio, I had to go back into audio settings and reconfigure, even though it claimed it was already set to the HDMI.
Very flaky with USB headsets right now.
Nothing extracted yet.
Logitech OEM PC 960 USB Stereo Headset works perfectly on Ubuntu with Steam, but on SteamOS the volume up and down buttons don't actually change the volume in SteamOS.
If this is the same as other headsets, it will be a problem as there's no real other way to adjust overall volume apart from going into every game and turning them down in the settings (which then screws the volume up when you take the headphones out).
It's also annoying to have ALL volume through my headset. Could you let us keep game audio to the TV? It's simple to do with pulseaudio and would match PS4/XBone too. Having voice and game audio in headsets is hard to manage/hard to hear people talking.