Symptoms
Users can’t use Outlook on the web (OWA), Exchange Control Panel (ECP), or the Exchange admin center (EAC) for a long time after an authentication certificate is published for servers that are set to the UTC time zone or any UTC+<#> time zone.
The new authentication certificate remains invalid for the specific UTC+ hours that are configured on the server. For example, If server time zone is UTC+8, the certificate remains invalid for 8 hours.
Resolution
To fix this issue, install the following updates, as appropriate:
Cumulative Update 12 for Exchange Server 2019 or a later cumulative update for Exchange Server 2019
Cumulative Update 23 for Exchange Server 2016 or a later cumulative update for Exchange Server 2016
