After upgrading to plasma 5.11 I don't get anymore the "feedback sounds" when changing the system volume through my keyboard. The volume of "Notification Sounds" in the KCM is definitely unmuted: I can hear the notification sounds in KMessageBox and friends. So I think this issue is not related to https://bugs.kde.org/show_bug.cgi?id=367688 If I install pavucontrol I get these sounds back, but if I uninstall pavucontrol and restart plasmashell, they are gone again.
And your distro is? You need to have libcanberra and libcanberra-pulse installed for this to work.
Right, I can see the issue. pavucontrol have libcanberra-pulse as dependency which gets uninstalled with it. It should be fixed in Arch packages.
Ah, I see. Thanks for checking. @arojas: could you have a look?
Fixed in 5.10.5-2 and 5.10.95-2