After BIOS upgrade, audio has not worked corretly, and audio did not appear from speaker but headphones worked, so the cure seems to be in Mint 20 to edit /usr/share/pulseaudio/alsa-mixer/paths/analog-output.conf file by adding lines and after editding restart pulseaudio.

sudo nano /usr/share/pulseaudio/alsa-mixer/paths/analog-output.conf

….. add lines

[Element Speaker]
switch = off
volume = merge
override-map.1 = all
override-map.2 = all-left,all-right

[Element Headphone]
required-any = any
switch = mute
volume = off

….. save, quit and restart pulseaudio

Ctrl o
Ctrl x

pulseaudio -k && pulseaudio --start

To test sounds, run

aplay -l

You can test the output using command. If card 0 and device 0

aplay -D plughw:0,0 /usr/share/sounds/alsa/Front_Center.wav