Zoom phone works on phone app but not on PC app

Hi

This is a new problem. Everything worked fine yesterday so it is not a problem with internet connectivity, firewalls etc. etc.

I have Zoom phone. Today I find that it works on two different Android phones when using the Zoom app but does not work on two different PCs. On the PCs, I can dial and connect but cannot hear or be heard.

Thanks for your help

Mitch