Microsoft 365 Alert – Service Degradation – Microsoft Defender XDR – Microsoft Defender for Identity V3 sensor was disconnected and not syncing Active Directory entities – RESOLVED

22/10/2025 09:28:00 AM

NHSmail Reference: INC46717526

Microsoft Reference: DZ1213976

Issue Status: RESOLVED

Issue Description: Microsoft Defender for Identity V3 sensor was disconnected and not syncing Active Directory entities.

More info: The activity stream was still functioning, and there was no regression. As a result, some activities did not show the most recent information from the on-premises environment. Certain experiences were affected by the delay in receiving the latest on-premises entity data.

Current Update: 06/01/2026 15:34:00 AM – Microsoft has determined that a recent update was not fully applied to some service components, which prevented them from picking up the latest configuration needed to operate correctly and led to the observed impact. They have redeployed the update, and monitoring confirms that the issue has been resolved.

Scope of impact: Your organization was affected by this event, and some users expecting the Microsoft Defender for Identity v3 sensor to sync the latest Active Directory entity data were impacted.

Root cause: A recent update was not fully applied to some service components, which prevented them from picking up the latest configuration needed to operate correctly and led to the observed impact.

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