I have using Zorin OS 16 for some months now. I have never had this problem. The audio input does not seem to work. I have tried using my headphones which also work on my phone. It also doesn't pick up anything without the headphones.
I tried running pavucontrol. It is picking up the headphones but does record anything.
I have also tried live booting into Pop Os and the same problem persists.
Here is some info