Microsoft 365 Alert – Service Degradation – Microsoft 365 suite – Some users may intermittently be unable to access, or may experience latency with various Microsoft 365 services – RESOLVED

10/06/2025 08:40:00 AM

NHSmail Reference: INC46550807

Microsoft Reference: MO1090542

Issue Status: RESOLVED

Issue Description: Some users may intermittently be unable to access, or may experience latency with various Microsoft 365 services.

More info: This issue affected a small subset of users intermittently and most users would likely have not encountered this issue. Affected users may have seen the following error message while attempting to access impacted services, “503 Service Temporarily Unavailable”. Examples of some impacted Microsoft 365 services were Microsoft Fabric, Power BI, and SharePoint Online. Additionally, Microsoft Defender for Cloud Apps was affected specifically when users or admins leveraged Conditional Access App Control (CAAC) actions.

Final Update: 10/06/2025 08:42:00 AM – Microsoft have completed implementing improvements on the portion of infrastructure and confirmed with monitoring internal telemetry that the impact is remediated.

Scope of impact: A small subset of users who were attempting to access various Microsoft 365 services may have been intermittently affected.

Root cause: A portion of infrastructure responsible for accessing various Microsoft 365 services wasn’t performing as efficiently as possible and resulted in timeouts when users attempt to access the affected services and applications.

Next steps: Microsoft are further investigating why the portion of infrastructure wasn’t performing as efficiently as expected so that we can help prevent similar problems from reoccurring.