Microsoft 365 Alert – Service Degradation – Microsoft Teams – Some users may have been unable to sign-in to the Microsoft Teams iOS application – RESOLVED

03/10/2023 09:28:00 AM (GMT)

NHSmail Reference : INC38633484

Microsoft Reference : TM678744

Issue Status : RESOLVED

Issue Description : Users may have been unable to sign-in to the Microsoft Teams iOS application.

More info : This issue was specific to some users that weren’t already signed in to the Microsoft Teams iOS application and whose SkypeTokens expired. Furthermore, users whose SkypeTokens expired while being signed in to the service may have been prompted for re-authentication, and subsequently may have been unable to sign in to the Microsoft Teams iOS application.

Final Update : 03/10/2023 09:28:00 AM – Microsoft identified that a section of authentication infrastructure, responsible for regulating sign-in for the Microsoft Teams iOS application, was unexpectedly operating below acceptable thresholds and causing impact. They observed their automated recovery systems return the service to expected performance levels, and subsequently confirmed following a monitoring period that impact has been remediated.

Scope of impact : Impact was specific to some users who were served through the affected infrastructure.

Root cause : A section of authentication infrastructure, responsible for regulating sign-in for the Microsoft Teams iOS application, was unexpectedly operating below acceptable thresholds and causing impact.

Next steps : Microsoft are reviewing their Microsoft Teams iOS application sign-in authentication procedures to reduce or avoid similar impact in the future.