Sound problem with 20.04

I'm running 20.04 on 4G RPi4b, with monitor connected to port0. I've modified usercfg.txt to force sound via HDMI regardless of what the EDID says.
I find that I have to play with sound settings as the setings result in no sound as supplied at boot. I can see no indication which of the two ports is which in the sound settings.
This curiosity applies also in the case of the monitor fed by VGA through an adapter, and also manifests for 18,04.
Any suggestions?

I had exactly the same problem. I have now installed the latest image for Ubuntu Mate Desktop (not via desktopify script from Ubuntu Server) and I still have to change the audio output each time after reboot (I have to select the second HDMI). At least it works now...

Thanks for the comment.
Using the HDMI0 labelled port (nearest the power input), I have to make two changes in audio settings - in each case to the second on the list - and I cannot close the settings window or it loses the setting and reverts.
I did find a posting about setting the default ALSA mixer setting - but found I couldn't make the settings as both ports are labelled identically in the diagnostic suggested.

I have only 1 HDMI connected for monitor
By default sound comes out on headphone jack

i don't use headphone jack so i but this off in sound setting: hardware (= 1st one)
result: only 2d (= HDMI) stay's active.

I reboot and stil have sound coming out HDMI

my sytem:
RPi4 4 Gb
Ubuntu Mate-raspi 64 bit
OS version 5.4.0-1015-raspi

I have the exact same problem. I can change the sound setting via Control Center and Sound selection and the sound works fine in all applications. How do I change the default settings for the sound to what I need on startup or reboot? I think it could be done via Terminal. Anybody out there have the answers!