Many headphones have inbuilt microphones and, as a result, the headphone jack has one more contact than those that do not have inbuilt microphones.
Performing a fresh install of PulseAudio after removing all configurations.By suspending and unsuspending the computer, the problem is usually fixed and headphones will now appear in sound settings.Simply plug headphones into computer but headphones don't appear in sound settings.Be running computer with headphones disconnected using another audio output.I'm certain that the issue is with Ubuntu 20.04 because the issue was not occurring (as far as I'm aware) when the same computer was running 18.04. I'm running Ubuntu 20.04 on a custom built computer with a B450 Tomahawk motherboard. The issue that I'm having is that headphones plugged into the 3.5mm jack on the front of my desktop computer are not always detected.
