They can't hear me and I can't hear them

My Zoom meeting on my Macbook Pro doesn't allow the participants to hear me nor me to hear them.

In System Preferences > Security and Privacy > Camera (and Microphone) Zoom is given access to camera and microphone. And when testing my audio on Zoom, both my mic and speakers work correctly.

But while in meeting it's dead silence for me and my participant...

What should I do?

Thanks!