Unable to type and speak same time in Zoom MAC OSX

Off late, I have been experiencing issues speaking and typing at the same time. 

While taking zoom access of customer's PC, I lose Keyboard access when customer is speaking. I had to use the mouse, click on the webex to get the keyboard access back. 

It happens when I speak or when customer speaks. 

MAC gives system warning tone when i try to type something when the person at the other end is speaking. 

Hence I wanted to check what's causing this and how can I type seamlessly while I or the customer is speaking.