Users may be unable to view recent portions of their conversation history with Microsoft 365 Copilot Chat

Timeline

Every update Microsoft posted for this issue, newest first.

1. Oct 29, 2026, 22:50 CET

   We're analyzing newly provided diagnostic data from affected users alongside our service logs to help isolate the source of the issue.
   
   This quick update is designed to give the latest information on this issue.

2. Oct 29, 2026, 21:58 CET

   We're working to trace how impacted conversation history requests are moving through each layer of our service to identify any potential inconsistences in routing behavior. We're also reviewing recent diagnostic data from affected users, which will inform our next steps toward remediation.

3. Oct 29, 2026, 19:59 CET

   Our review of support cases and service telemetry has identified an issue with how some Copilot Chat requests are directed to our service infrastructure. Requests from the same user can intermittently be sent to different parts of our infrastructure, so a conversation may sometimes load an earlier version of its history that doesn't include the latest exchanges. We're working to determine why these requests aren't being consistently directed, so that we can develop a fix that ensures users always see their complete conversation history.

4. Oct 29, 2026, 18:43 CET

   We're reviewing support cases to further our understanding of the current impact scenario and to determine our next troubleshooting steps.

5. Oct 29, 2026, 18:21 CET

   We're investigating a potential issue with Microsoft 365 Copilot Chat and checking for impact to your organization. We'll provide an update within 30 minutes.