Microsoft 365 Alert – Service Degradation – Microsoft Copilot (Microsoft 365) – Users’ prompts to Copilot Studio agents that leveraged the Microsoft Teams channel connector may have failed – RESOLVED

28/05/2026 09:38:00 AM

NHSmail Reference: INC46836953

Microsoft Reference: CP1323874

Issue Status: RESOLVED

Issue Description: Users’ prompts to Copilot Studio agents that leveraged the Microsoft Teams channel connector may have failed.

Final Update: 26/05/2026 09:33:00 AM– After analyzing conversation IDs provided by a subset of affected users, Microsoft has isolated that a recent update intended to allow the acquisition of authentication components using Copilot Studio agents on behalf of the user introduced a regression that caused authentication checks to fail as they weren’t provisioned to the user completing the request. They have rolled back the offending change and validated with a subset of affected tenants that their actions successfully remediated impact.

Scope of impact: Users prompting Copilot Studio agents that leverage the Microsoft Teams channel connector may have had prompts fail to generate.

Root cause: A recent update intended to allow the acquisition of authentication components using Copilot Studio agents on behalf of the user introduced a regression that caused authentication checks to fail as they weren’t provisioned to the user completing the request.

Next Steps: Microsoft are analyzing the offending update to isolate why the potential for impact wasn’t caught during their internal update testing and validation phases. This further analysis will help them to improve their update implementation processes moving forward to ensure similar impact scenarios don’t occur in the future.