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 – ONGOING

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: 11/05/2026 10:13:00 AM – While performing internal testing of Microsoft solution to correct the problematic code, they determined a change was needed to ensure the fix fully remediates the impact. They have made this change to the fix and they are progressing with their validations ahead of deployment. They now anticipate their deployment will complete by June 26, 2026, and they will continue to assess their projected timeline as internal testing continues.

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: Wednesday, June 10, 2026, at 10:00 PM UTC