In scope of "CSHARP-5560: CSOT: Refactor IOperationExecutor to use operation context" I've noticed that MongoClient implementation does not use ChannelPinningHelper like MongoCollection or MongoDatabase. As the result there were added optional parameter to OperationExecutor to disable channel pinning. We need to investigate why mongo client do not use pin the channel (it might be a bug) and remove the parameter if we decide that channel should be pinned here as well.