Microsoft 365 Alert – Service Degradation – Exchange Online – Users may be unable to view free/busy status for Gmail users within the Exchange Online calendar – ONGOING

22/05/2026 08:31:00 AM

NHSmail Reference: INC46832712

Microsoft Reference: EX1310533

Issue Status: ONGOING

Issue Description: Users may be unable to view free/busy status for Gmail users within the Exchange Online calendar.

More info: Impacted admins may experience a point-in-time gap of approximately 30 minutes in Microsoft Defender for Endpoint telemetry data when viewing information in the Microsoft Defender portal and Microsoft Sentinel, as the impacted data wasn’t ingested.

Current Update: 22/05/2026 08:31:00 AM–Microsoft has completed the development of their code fix, and validation of the fix within our internal testing environment is underway. They will provide a timeline for deployment as one becomes available.

Scope of impact: Impact is specific to any user attempting to view free/busy status for Gmail contacts in their Exchange Online calendars.

Root cause: A feature was recently disabled to mitigate an unrelated event, resulting in this impact.

Next update by: Friday, May 22, 2026, at 7:30 PM UTC