I have mpd enabled as a herd service. When I start my computer, mpd can play my music fine, but pavucontrol can't connect to pulse and show my volume controls. If I kill pulse and open pavucontrol, all my volume controls are visible, but then mpd can't play music. If I kill pulse again and this time play a song in mpd, mpd works again, but pavucontrol can't connect. Basically, if mpd starts pulse, mpd works, but other things can't connect, and if pavucontrol starts pulse, mpd can't connect to pulse. Since I have mpd enabled as a service, it's the one to start pulse on a fresh boot. I also tried starting pulse as my user by killing it and opening pavucontrol, then restarting the mpd service in case it could find my pulse service this way. No success there. While mpd has control of pulse, other applications also lack sounds, such as mpv (video players) and icecat.
mpd version: 0.20.20