strange loopback behaviour seen in alsamixer

[Dr. Jochen Blödorn]

hi,
while debugging my sound setup in Xubuntu 18.4, I came up on some strange
behaviour.
Reason for debugging was, I couldn't play rear line input to line output.
To check, if I missed some basic settings I started alsamixer.

As I always do, I toggled each setting, to make sure, that the displayed
status reflects it's actual state. This routine is one relict from my old
windows times :-)

When I applied this method to "loopback", which initially was displayed as
"enabled" ( switch from enabled to disabled and back to enabled), I
instantly got sound output. This can, and must be, reproduced after every
restart of the desktop.

Sorry, if I posted this mail wrong way, wrong place, but I thought, the
observation might be of interest.

Jochen