Some users may see multiple impact scenarios for Microsoft Copilot Researcher

Title: Some users may see multiple impact scenarios for Microsoft Copilot Researcher User impact: Users may have seen multiple impact scenarios for Microsoft Copilot Researcher. More info: Specifically, users may have seen reauthentication prompts, failed queries, incomplete grounding, or query latency in Microsoft Copilot Researcher Final status: We've completed our analysis of the system logs and service health telemetry, and we pinpointed a recent update to the Microsoft Copilot Researcher service incorrectly balanced a high volume of traffic, causing requests to be routed to a portion of infrastructure that didn't have the processing availability to meet the unusual increase in demand and leading to impact. We've disabled this update and confirmed through our monitoring that the service health has returned to normal, and impact has been remediated. Scope of impact: Impact was limited to a small subset of users hosted on the affected infrastructure. Start time: Tuesday, June 16, 2026, at 2:00 PM UTC End time: Thursday, June 18, 2026, at 1:05 AM UTC Root cause: A recent update to the Microsoft Copilot Researcher service incorrectly balanced a high volume of traffic, causing requests to be routed to a portion of infrastructure that didn't have the processing availability to meet the unusual increase in demand and leading to impact. Next steps: - We’re analyzing performance data associated with the impacted Microsoft Copilot Researcher scenarios infrastructure following the recent update to better understand what caused the imbalance and prevent similar impact from occurring again in the future. This is the final update for the event.

Title: Some users may see multiple impact scenarios for Microsoft Copilot Researcher User impact: Users may see multiple impact scenarios for Microsoft Copilot Researcher. More info: Specifically, users may see reauthentication prompts, failed queries, incomplete grounding, or query latency in Microsoft Copilot Researcher Current status: We're reviewing system logs to isolate the origin of this issue. Scope of impact: Impact is limited to a small subset of users hosted on the affected infrastructure. This information may be updated as our investigation continues. Next update by: Thursday, June 18, 2026, at 2:00 AM UTC