Applications are muted (silent) but system sounds work

[Joseph Maillardet]

How to reproduce this bug:

* Connect a laptop to a dock, which is connected to a screen with an HDMI / DisplayPort cable.
* Then configure the sound to exit through the cable connecting the screen.
* Turn off the computer
* Take it out of the dock
* Turn on the computer

Then, the sound automatically switches to the audio output of the laptop. System sounds work well, such as the bell of output volume slider or the test speaker buttons “front left” or “front right”. Unfortunately, no more applications can produce a sound.

Graphically, applications react normally, we can see their connections with pulse audio in the applications tab of the sound settings. But no sound comes out of the speakers.

Workaround :
* Connect an alternative audio output, such as a Bluetooth headset
* Select it in the “Choose a device for sound output:” option
* Switch back to the internal audio speakers
* Et voilà !

If it help, my laptop is a “HP Zbook G2” sometime connected to a “HP 2012 230W Docking Station”

Thank you for your attention.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: gnome-control-center 1:3.28.1-0ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
CurrentDesktop: GNOME
Date: Thu May 3 09:21:01 2018
EcryptfsInUse: Yes
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-control-center
UpgradeStatus: Upgraded to bionic on 2018-04-24 (8 days ago)

[Sebastien Bacher (seb128)]

gnome-control-center is only involved in applying configuration changes, it's not a service and not active/playing a part in what is happening after rebooting on disconnecting devices, reassigning to pulseaudio

When you play sound in an application, do you see that one added to the 'applications' tab from the sound settings? is the volume muted/low there?

[Joseph Maillardet (jokx)]

Has I say in my report : "Graphically, applications react normally, we can see their connections with pulse audio in the applications tab of the sound settings. But no sound comes out of the speakers."

At UI level, everything seem to work, application volume is not mutted. The stranger thing is that gnome feedback sound work where application sound (mpv, firefox, ...) don't.

[Launchpad Janitor (janitor)]

[Expired for pulseaudio (Ubuntu) because there has been no activity for 60 days.]