Dear Maintainer,

To switch to another user, let's say "testuser", while my normal user is
"gusnan", I open pavucontrol, turn off sound on active user gusnan, by
changing the profile for my sound card "UMC204HD 192k", from "Direct
UMC204HD 192k" to "Off", switch user by the Xfce menu, which gets me to
lightdm, logging in to my "testuser" user, there set the sound card
(since I want sound there, which I don't get otherwise). All fine and
everything works as it should.

When I then want to go back I log out (or switch user and before that
turn off sound for "testuser", the result is the same) -

when I have logged in to user "gusnan" again, IF I didn't close the
pavucontrol window previously on user "gusnan", the X system is
somewhat locked. I can move the mouse, but clicks do little or nothing
and the system is more or less unusable.

On the other hand IF I do exactly the same, but close the pavucontrol
window after turning off sound for "gusnan" before switching to
"testuser", then everything works fine when coming back to user "gusnan".

If I get the system locked like this, the solution I have found is to
switch to a console, kill the pavucontrol process, which unlocks the X
system, and everything works as it should after that when switching
back to X.