Microsoft 365 Alert – Service Degradation – Microsoft Teams – Admins may be unable to enforce Data Loss Prevention (DLP) policies in Microsoft Teams – RESOLVED

23/07/2026 09:21:00 AM

NHS.net Connect Reference: INC46888495

Microsoft Reference: TM1436888

Issue Status: RESOLVED

Issue Description: Admins may have been unable to enforce DLP policies in Microsoft Teams.

More info: DLP policies configured in Microsoft Purview successfully detected policy matches, but the expected enforcement actions weren’t being applied within Microsoft Teams. As a result, messages that should have been blocked may have continued to be delivered. This applied to all Microsoft Teams channels.

Final Update: 23/07/2026 09:23:00 AM – Microsoft has validated through their testing that an authentication configuration change made to the service infrastructure affected the enforcement of DLP policies, which led to impact. They have successfully deployed their fix to roll back this configuration change in all environments and confirmed that impact has been resolved.

Scope of impact: Any admin may have been impacted and may have been unable to enforce DLP policies in Microsoft Teams.

Root steps: Microsoft is reviewing their feature update testing and validation methods to better identify the potential for impact to DLP policies prior to deployment to prevent similar impact in the future, and to improve their pre-deployment update testing processes.