If you scroll to the Last answer provided "In 2020," and try the steps outlined there; it may be a good starting point.
Please be sure to also check that your Mic Volume is not set to higher than 40% in the pavucontrol settings:
sudo apt install pavucontrol
pavucontrol
If no luck there, please update this thread. Pulseaudio and its modules are... interesting... with sound and mic issues. It may take a lot of troubleshooting.
EDIT: This thread makes a point about how OBS does not use any noise suppression:
I also stumbled on this Video guide with a proposed fix...;
