Microsoft 365 Alert – Service Degradation – Microsoft Defender XDR – Users may be missing some device timeline and advanced hunting events in the Microsoft Defender for Endpoint portal – RESOLVED

Announcements Arpan Das

29/09/2025 09:01:00 AM

NHSmail Reference: INC46641709

Microsoft Reference: DZ1160098

Issue Status: RESOLVED

Issue Description: Users may be missing some device timeline and advanced hunting events in the Microsoft Defender for Endpoint portal

More info: This issue only impacts some workstation endpoints and not servers.

Final Update: 30/09/2025 14:10:00 PM – Microsoft have confirmed after a period of monitoring that impact is no longer occurring.

Scope of impact: This issue may impact some users’ workstation, and some device timeline and advanced hunting events may be missing in the Microsoft Defender for Endpoint portal.

Root cause: A recent change to provide updates to the mechanism of data collection for timeline and advanced hunting events is resulting in impact.

Next Steps: Microsoft are reviewing their recent change procedures to help prevent similar impact from happening again.