Just like the many people who tried to uninstall PA, I too consider PA as a trouble maker.
Examples are as gross as opening a second session and having no sound in it.
Pulseaudio should be optional, made for those who run one session and one sound program at a time and require sound features pertaining to a Studio.
Yes this is a bug and not a wish.
Ubuntu is a system where the volume applet may not control the volume and the general user is advised to fumble about to determine which of the 10 sliders he can find will do it, Such features raise pellets of laughter from the disparagers who say it's a system for hackers.
It's very surprising to find a "Pulseaudio Sound System" to uncheck, to read that "it is not the way you disable PA" without saying how you do disable it, followed by "if you disable PA then..."