Comment 13 for bug 1764965

@Jacopo, I think this problem may be an incompatibility issue between the PulseAudio driver (if driver is the correct term) and the ALC1220 chipset/codec. I used this procedure to disable PulseAudio and found that I could record normally (link follows):

https://kodi.wiki/view/PulseAudio/HOW-TO:_Disable_PulseAudio_and_use_ALSA_(without_removing_PulseAudio)_for_Ubuntu

Disabling PulseAudio will also disable HDMI out. I use the affected machine for home theater so I must enable PulseAudio for that. The linked procedure is simple but requires some time and a reboot. Ultimately, it would be nice for a computer coder (perhaps associated with PulseAudio) to get PulseAudio to work with the ALC1220 chipset/codec.