If your audio or your guest's audio is stuck on mute and you're unable to unmute, here's how to fix it:
The person whose microphone is muted should click the "Change Camera & Mic" button at the top of their video.
Once they click on that, they'll see a popup where they can select and confirm their video and microphone inputs.
If both the camera and mic are correct and the mic is responsive, click save and the video feed will be refreshed with the new audio input; with the mic unmuted and functioning properly.
What causes this to happen?
This is usually caused when a person disconnects and/or connects microphone/headphones while on screen.