We have been notified by Microsoft that some of their authentication systems are experiencing problems. You might experience issues attempting to authenticate to Teams and other MS services.
Message from Microsoft:
Authentication errors across multiple Microsoft services - Investigating
SUMMARY OF IMPACT: Starting at approximately 19:15 UTC on 15 Mar 2021, a subset of customers may experience issues authenticating into Microsoft services, including Microsoft Teams, Office and/or Dynamics, Xbox Live, and the Azure Portal. CURRENT STATUS: Engineering teams have been engaged and are currently investigating. The next update will be provided in 60 minutes or as events warrant.
To check the status of Microsoft systems: https://status.azure.com/en-us/status
Office of Information Technology Services