If other solutions don't work, during a Zoom call/session try this: Click on the up arrow next to "mute/unmute" and make sure "Same as System" is checked under "Select a Speaker" and "Select a Microphone."
If other solutions don't work, during a Zoom call/session try this: Click on the up arrow next to "mute/unmute" and make sure "Same as System" is checked under "Select a Speaker" and "Select a Microphone."