Not sure if this would solve your problem, but have you tried companion mode?

I think the other party would need to try it? I'm using a headset, the feedback is coming from the other party.

The problem is the other half of the company that never use it.

Do you mean audio feedback, or just one user that complains a lot?

I'm talking about when I hear my own voice. It happens when the person I am talking to is using speakers and a microphone, and my voice is picked up by their speakers and transmitted back to me. I didn't know this was controversial.

FYI, that's echo, not feedback.

It can happen on any service and it means the echo cancellation on their end got confused -- it's an adaptive algorithm but occasionally adapts wrong.

Best way to fix it is to mute yourself for ~5 seconds and then unmute, which should reset their echo cancellation algorithm.

If that doesn't fix it, then have both of you pause and not talk for ~5 seconds. This should absolutely reset it, as the echo cancellation algorithm has now definitively learned what silence is supposed to sound like.