Microsoft 365 Alert – Service Degradation – Microsoft Teams – Users may be unable to join town halls in Microsoft Teams using iOS 26.5 version and get an error message – ONGOING

Announcements Shagufta Naaz

21/05/2026 08:30:00 AM

NHSmail Reference: INC46832370

Microsoft Reference: TM1317239

Issue Status: ONGOING

Issue Description: Users may be unable to join town halls in Microsoft Teams using iOS 26.5 version and get an error message.

Current Update: 21/05/2026 08:30:00 AM–Microsoft has completed the validation process for our potential solution and are preparing it for deployment. They anticipate being able to provide a deployment timeline by their next scheduled communications update.

Scope of impact: Some admins relying on security telemetry reporting in Microsoft Defender for Endpoint may be impacted. This information may be updated as our investigation continues.

Root cause: Any user attempting to join town halls in Microsoft Teams using iOS 26.5 version may be affected by this issue. This section may be updated as our investigation continues.

Next update by: Friday, May 22, 2026, at 1:00 AM UTC