The portal policy is configured to include Google Suite headers to control logins to personal accounts. With this policy configured, we have observed that when a user is logged in to the Chome browser with his personal Gmail profile then he is unable to join the Google Meet meeting.
Users can join the Google Meet meeting from an incognito window and/or Google Chrome browser without any personal Gmail profile logged in.
Create a Header modification rule for the meet.google.com destination domain to delete the custom header X-GoogApps-Allowed-Domains above the actual Google header modification policy rule for the google.com destination domain then activate the policy.
The header modification rules order should be as mentioned in the following snapshot
For header modification Rule#1 detail refers to the following snapshot
For header modification Rule#2 detail refers to the following snapshot