Follow-up investigation to DEVPROD-41561: Investigate MCI latency spikes. 

The original investigation ruled out potential Evergreen-side explanations and identified a recurring database-side execution-queue ticket-wait pattern that remains unresolved. daniel.gomezferro@mongodb.com Identified a  2026-09-08 event that appears representative: execution-queue ticket wait rose from approximately 0 to a 3.16M-second peak, ingress wait remained 0, disk I/O and arrival rate were flat, and the behavior was isolated to the primary on shard-00-01. 

daniel.gomezferro@mongodb.com and meryama.nadim@mongodb.com are currently investigating the issue from two different angles. This ticket is meant to track that work, capture any findings, and recommend any next steps if necessary. 

For more information, please see the investigation summary for DEVPROD-41561.