Firefox don't respect sound settings.

[Petr Olexa]

Firefox don't respect sound settings. Keeps using internal output device (default) instead of selected one (HDMI).

Other applications respects that and works fine (chrome, vlc ...) only firefox have this problem.

This problem appears after upgrade to 20.04

I tried to change graphic card and also drivers but the problem persists.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: firefox 84.0.1+build1-0ubuntu0.20.04.1
ProcVersionSignature: Ubuntu 5.4.0-58.64-generic 5.4.73
Uname: Linux 5.4.0-58-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
AddonCompatCheckDisabled: False
ApportVersion: 2.20.11-0ubuntu27.14
Architecture: amd64
BuildID: 20201221152838
CasperMD5CheckResult: skip
Channel: Unavailable
CurrentDesktop: ubuntu:GNOME
Date: Wed Jan 6 12:06:52 2021
ExecutablePath: /usr/lib/firefox/firefox
Extensions: extensions.sqlite corrupt or missing
ForcedLayersAccel: False
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
IncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite)
InstallationDate: Installed on 2016-08-06 (1614 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
Locales: extensions.sqlite corrupt or missing
MostRecentCrashID: bp-5a576006-0903-42d0-95cb-b051d1180511
PrefErrors: Unexpected character ',' before close parenthesis @ /usr/lib/firefox/omni.ja:greprefs.js:354
PrefSources: prefs.js
Profiles: Profile0 (Default) - LastVersion=84.0.1/20201221152838 (In use)
RunningIncompatibleAddons: False
SourcePackage: firefox
SubmittedCrashIDs: bp-5a576006-0903-42d0-95cb-b051d1180511
Themes: extensions.sqlite corrupt or missing
UpgradeStatus: Upgraded to focal on 2020-08-27 (132 days ago)
dmi.bios.date: 10/31/2014
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: FB
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: 970A-DS3P
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrFB:bd10/31/2014:svnGigabyteTechnologyCo.,Ltd.:pnTobefilledbyO.E.M.:pvrTobefilledbyO.E.M.:rvnGigabyteTechnologyCo.,Ltd.:rn970A-DS3P:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.family: To be filled by O.E.M.
dmi.product.name: To be filled by O.E.M.
dmi.product.sku: To be filled by O.E.M.
dmi.product.version: To be filled by O.E.M.
dmi.sys.vendor: Gigabyte Technology Co., Ltd.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Petr Olexa (olexap)]

Found temporary solution.

When I install pavucontrol, there I am able to switch sound output on running application (including firefox). But later when I change setup (turn on or off my TV) then I must do it again this way.

Therefore I am unable to control my sound output using built-in sound controls in ubuntu (gnome) desktop and only possible way is to try another applications.