When I'm on a group call on Zoom, I've noticed if there's any audio coming out of my speakers, my mic won't pick up my voice. So if there's background noise coming from someone else's computer, or if someone else is speaking, it's like my mic mutes itself. Other people on the call will come through, even if they speak at the same time. My solution has been to use headphones, but others don't seem to have this issue, even if they aren't using headphones. I'm using an Apple iMac on Zoom, and my friend has the same problem with a MacBook Air. Any ideas?