Title: Some Exchange Online users may intermittently be unable to view free/busy information of Exchange on-premises users
User impact: Exchange Online users may intermittently be unable to view free/busy information of Exchange on-premises users.
Current status: We’ve successfully rolled back the change and are now in the process of contacting some affected users who were impacted to verify that the issue has been resolved.
Scope of impact: This event may intermittently impact some users who attempting to retrieve external users’ free/busy information in Exchange Online.
Start time: Saturday, March 30, 2024, at 12:00 AM UTC
Root cause: A configuration change is causing incorrect results to be returned by a portion of service infrastructure that manages requests sent between Exchange Online and on-premises Exchange Online users.
Next update by: Saturday, April 13, 2024, at 9:00 PM UTC