Audio lagging behind is often caused by latency in your network (or your patient's network connection).
Try refreshing the page and starting the call again. Ensure you and your patient have a good network connection. You need at least 750 kb/s upload and download speeds.
You can also make sure no other programs are running in the background of the computer/phones/tablets. Having multiple programs running can slow the connection.
If you are still having issues after trying these steps, contact our support team.