There will be an dummy output if
- no built-in speaker - no headphone/earphone plugged - using display (like VGA, DVI) without audio out is plugged.
Reprudced in bionic and focal.
In Focal, As the earphone is plugged, dummy output disappears. As it's unplugged, it appears again.
Per test in focal: pulseaudio 1:13.0-3ubuntu2 gnome-control-center 1:3.35.91-0ubuntu1
There will be an dummy output if
- no built-in speaker
- no headphone/earphone plugged
- using display (like VGA, DVI) without audio out is plugged.
Reprudced in bionic and focal.
In Focal, As the earphone is plugged, dummy output disappears.
As it's unplugged, it appears again.
Per test in focal: center 1:3.35.91-0ubuntu1
pulseaudio 1:13.0-3ubuntu2
gnome-control-