For some reason something keeps muting system sounds. I am not doing it intentionally.
Thats odd but some more details might help.
Are you using some sort of headset? Does it happen if you are running certain applications or is this just random.
No, no headsets. Seems random. I do use multiple output devices that are often switched around. Sometimes I will shunt sounds off to the TV via HDMI through the graphics card, and analog HiFi audio to my HES via my external recording interface (two discrete stereo outputs or 4 discrete mono recording channels, with Stereo A driving my bi-amped KRK near field monitors via XLR on my workstation, and Stereo B driving my Rotel HES hifi via RCA).
Currently I am just using the HDMI to the TV and Channel A. Channel B is active, but not in use unless I turn on the hifi and open an audio app (Audacious).
The built in Intel 7.1 sound is disabled in the bios.
The only other thing I have noticed is that both Haruna and Dragon player think they are VLC. When VLC is muted, so are Haruna and Dragon. Dragon requires going into sound settings to unmute, as trying from the app fails. I keep just about every known video player for testing of media as I do media development professionally (photography, audio engineering, field recording, filmmaking).
Does Plasma think its VLC too I wonder? I will test out VLC mute to see if it triggers the system sound mute.