in a call with a couple, one was able to see and hear each other. The other was only able to see. He could hear me but not his spouse. Both were on their phones and in a car for privacy.
This happened to me. After researching the issue I realized I was connecting the 2nd client wrong. After connecting with the first client, click on the word “Group Call” in the list on the left on the dashboard. It will open a new window which will list those ready to join.