Some European customers of Microsoft 365 hit connectivity problems on the day Office 2021 LTSC reached end of support. The affected service was Global Secure Access, which customers use to reach Outlook, OneDrive, SharePoint Online, Teams and Windows 365 Cloud PCs.
Microsoft said a section of that infrastructure was performing below acceptable thresholds and that it was applying traffic and performance optimisations.
Source: theregister.com, reported 10-13. https://www.theregister.com/saas/2026/10/13/microsoft-celebrates-end-of-office-2021-ltsc-with-ms-365-outage/5302848