Comment 9 for bug 1912052

First off, please try the latest kernel, at best 5.11. It makes further debugging easier.

After confirming the latest kernel still doesn't work, let's try to switch to the legacy HD-audio snd-hda-intel driver; we're checking only about the external mic, and it makes easier to debug, too. Boot with snd_intel_dspcfg.dsp_driver=1 boot option, and it'll forcibly use the legacy driver. Note that, with this, the built-in mic won't work with this.

Once after that, you can try to pass a different model option to snd-hda-intel module.