Microsoft 365 Alert – Service Degradation – Exchange Online – Users may be unable to reach agents through Dial-by-Extension for some auto attendants in Microsoft Teams – RESOLVED

03/03/2026 08:40:00 AM

NHSmail Reference: INC46762722

Microsoft Reference: TM1239087

Issue Status: RESOLVED

Issue Description: Users may be unable to reach agents through Dial-by-Extension for some auto attendants in Microsoft Teams.

More info: Users may have heard the greeting, followed by approximately 15 seconds of silence, then they may have received the error message: “Sorry, I couldn’t help.”

Final Update: 03/03/2026 08:40:00 AM – Further review determined that the recent service update caused a portion of the supporting Microsoft Teams service infrastructure to operate in a suboptimal state due to high CPU and memory constraint issues, resulting in impact. They have completed rolling back the offending service update, and confirmed through testing with a subset of affected users, as well as through monitoring service health telemetry that the impact has been remediated.

Scope of impact: Any admin or users attempting to access any Microsoft 365 services with the Microsoft 365 Group SecurityEnabled set to false may be impacted. This section may be updated as our investigation continues.

Root cause: A recent service update caused a portion of the supporting Microsoft Teams service infrastructure to operate in a suboptimal state due to high CPU and memory constraint issues, resulting in impact.

Next steps: Microsoft are reviewing our update procedures to understand why impact to auto attendant functionality wasn’t caught during the testing phase. This will allow us to drive service improvements by proactively identifying similar issues in the future and improve our update testing processes.