Microsoft 365 Alert – Service Degradation – Microsoft 365 suite – Some users may be unable to access multiple Microsoft 365 services using a specific Multi-Factor Authentication (MFA) – RESOLVED

22/03/2023 08:30:00 AM (GMT)

NHSmail Reference : INC34922293

Microsoft Reference : MO531385

Issue Status : RESOLVED

Issue Description : Some users may be unable to access multiple Microsoft 365 services using a specific Multi-Factor Authentication (MFA)

More Information : Impact is specific to users attempting to utilize the voice to office phone with extensions MFA method. As a workaround, users may be able to use alternate authentication methods to complete their sign in e.g. Authenticator application, Short Message Service (SMS) or Time-based one-time password (TOTP).

Final Update : 22/03/2023 09:29:00 AM –  Microsoft have successfully reverted the offending change and confirmed that service was restored after monitoring the environment.

Scope of impact : Your organization is affected by this event, and some users attempting to access multiple Microsoft 365 services using a specific MFA method may be impacted.

Root cause : An issue has occurred when updating the time zone information for Daylight Saving for users in Mexico, causing the reported impact.

Next steps : Microsoft are reviewing their standard service update procedures to better identify similar issues during their development and testing cycles.