This issue has been mitigated and we have not had further reports since 8AM EST / 1 PM GMT.
To fully address all the potential issues that can cause the problem an update will be completed overnight. We will update the advisory after all the work has been completed.
Update 10/05/2022 13:33 PM 13 days
We have received several reports from clients who were unable to login at admin.exchangedefender.com as Domain Admin or Service Providers. User login or service operation is not affected. We have rolled back our admin infrastructure to Tuesday (10/4/2022) version and service is back to normal.
We will update this advisory once the new codebase is in and we've been able to isolate the bug that is causing some administrators infinite 502 redirects.