Hello. I have unchecked 'volume feedback' checkbox in audio volume settings, but feedback is still present. Only muting notifications volume helps.
Do you have multiple instances of Volume applet? This option applies only to the instance from which you opened the settings.
I had two. When I removed one, it seems worked. So if I want to disable volume feedback, I need to uncheck checkbox for both?
Yes, you need to disable it in all volume applet instances, otherwise you will get feedback from each applet instance.