Hey everyone,
I’m new here and pretty new to Ubuntu as well but wanted to share how I fixed my dummy output issue. Initially I had the same issue where my Output device was designated as Dummy Output and nothing was visible in the Input Device, even after toggling the physical switch. The issue turned out the me with the official instructions for how to make the 3.5mm jack support, here. After Removing:
options snd-hda-intel model=dell-headset-multi
from:
/etc/modprobe.d/alsa-base.conf
Everything started working perfectly.
Hope this helps,
Cheers!