Microsoft 365 Alert – Service Degradation – Exchange Online – Users may see that after selecting a meeting room when scheduling meetings, it changes from available to unavailable – ONGONG

19/03/2026 09:25:00 AM

NHSmail Reference: INC46777325

Microsoft Reference: EX1233142

Issue Status: ONGOING

Issue Description: Users may see that after selecting a meeting room when scheduling meetings, it changes from available to unavailable.

More info: While we are working to remediate the impact, admins can mitigate the issue by assigning the desired working hours and the time zone for the meeting rooms.

Current Update: 29/06/2026 09:06:00 AM – Microsoft has confirmed that our fix encountered a deployment blocker that slowed progress. They have addressed the blocker and confirmed that the fix is deploying at a normal rate and has reached 25 percent of the affected environment. They will continue monitoring its progress to ensure it completes as expected by their next scheduled update. They are also reaching out to a subset of affected users to validate the fix ahead of schedule to expedite the deployment process.

Scope of impact: Any users that are trying to select a meeting room when scheduling meetings outside the room’s working hours in Exchange Online may be impacted. This information may be updated as our investigation continues.

Root cause: A recent expansion of the feature logic used to book rooms for scheduled meetings contains a code complication which automatically sets the meeting rooms’ default working hours to appear in Pacific Standard Time instead of their accurate time zone.

Next update by: Thursday, July 2, 2026, at 8:30 PM UTC