In 'multimedia' section of system settings, I can't set notifications volume. When I drag slider, it returns back to zero immediately. It never worked on my machine since Plasma 5.8.2. So I don't have any notifications. Plasma 5.9.4, Gentoo-hardened, kde-overlay unmasked, Linux-4.9.15 + Grsecurity (with paxctld and exceptions for most kde core).
Can you change it using pavucontrol?
I opened pavucontrol, and see list of playback streams, but very shortened. The first is "S..." and slider is totally disabled.
Can you please post screenshot?
Created attachment 104743 [details] pavucontrol. First slider is disabled spectacle sucks. Ksnapshot worked much better
You need to first unmute the stream with mute icon in top right corner.
I unmuted in pavucontrol and it worked. In audiovolume settings it also started working and slider is moving. But unmuting in 'audiovolume settings' was not working - slider was returning back. So for me it is resolved, but there is a bug in 'audiovolume settings'
*** Bug 378755 has been marked as a duplicate of this bug. ***
*** Bug 379183 has been marked as a duplicate of this bug. ***
*** This bug has been marked as a duplicate of bug 367688 ***