I installed Ubuntu 18.04 on my new HP elitebook 850 G6 after erasing windows. I could not get audio input part working though.. Fn F8 key is orange all the time and this is how settings looks like.
I installed pavucontrol, but that didn't change anything. What I have noticed is that I cannot check "set as fallback" permanently.
Also tried editing
/etc/modprobe.d/alsa-base.conf by adding
options snd-hda-intel model=auto
Sound control still does not recognize any microphone