For many children who have had problems signing onto their class live sessions via Google Meet, there appears to be a common issue:
Before you log your child into Google Classroom for the meeting please ensure that any sibling/other Hwb or Google accounts are 'signed out' of, on that device. When more than one account is signed in on a device Google isn't sure what account to use to access the meeting, which has been the cause of most failed sign-in attempts.
After clicking the Meet Link in your child's Google Classroom please check the initial in the circle found in the top right corner of the screen. This should be the child's initial who is trying to access the Google Meet. Click this circle to select the child's account, if the initial shown is incorrect.
We hope this is helpful.