FaceTime (or video calls with other apps) on Mac mini have audio feedback

I have a Mac mini M4 and it doesn't matter what webcam, mic, speaker combination I use video calls all suffer with terrible audio feedback.

Ive tried using different webcams (Logitech C920, and a Logitech Brio 500)

Ive tried using the built in Mac mini speaker, as well as some Creative Pebble V3 using bluetooth as well as the USB-C connection and nothing helps.

Using my iPhone as a webcam/mic works ok, but this isn't practical for me. Has anyone found a working combination of webcam/mic/speakers?

Ive been testing using FaceTime and WhatsApp.