Rotating the screen for the Raspberry Pi 4
Due to the new video driver used for by the Raspberry Pi 4, you are unable to rotate the screen using the old /boot/config.txt method.
If you want to rotate the screen on a Pi 4, we recommend that you use the Screen Configuration tool as it is much simpler to use.
Instead you will need to make use of the xrandr ...
I couldn't find a valid answer to this question but I found some hints suggesting that I might not need pulseaudio installed at all.
sudo apt-get purge pulseaudio
was all I needed to make the 3.5mm jack in RPi4 working even without HDMI plugged in.
Both VLC and chromium now play sound without any problems.
As pavucontrol has been removed with the pulseaudio ...