KDE disables audio when I plug a USB device

[philip]

I have a most strange problem with KDE disabling my audio when certain events happen on my PC.
The sound works as normal after boot.

One repeatable event is when I plug a USB memory. Then KDE show a message "Multimedia System, the audio playback device alsa does not work. Falling back to HDA Intel HDMI, HDMI 1 (HDMI Audio output)"

I do not know if still have sound in the HDMI output since I do not have a HDMI device to test this.

However the fact that I plug a USB device into the PC should not alter any sound settings. The sound works as normal after boot.

Has anyone else had these problems? IS this a KDe settings issue? Or is it a udev issue? Or anything else?

I would be greatful for some advice where to start a root casue analysis.
_________________
/Phil