When you have no sound at all, the likely explanation is that the sound is being routed to the device which you are not using, and thus although the sound is working you cannot hear it.
Maybe this would get your PulseAudio working .....
I have not lost sound. It continues to work, I assume through the previous configuration. I tried the suggestion in the post you listed but all I get is this:
E: [pulseaudio] main.c: Daemon startup without any loaded modules, refusing to work.
What does that mean? Are we getting closer?
That output often means that the required modules to have PulseAudio work have not been loaded for some reason.
So, PulseAudio is not presently enabled/working.
I do not know why this happens on some installs and not on others
What I suggest is the following .... to see if it will help .......
disable PA in PCC - Hardware - Sound and reboot immediately
immediately on reboot, enable PA again, and shut off the PC, and withdraw power for ~1 min
Power up again and after the DE has settled try opening pavucontrol and report back what you see.
Hopefully that should get it working .......