The following is a modified jstests/core/list_all_sessions.js test which demonstrates this issue. The following will pass when run against the core suite but will fail against the sharding_jscore_passthrough suite:   // Sessions are asynchronously flushed to disk, so a stepdown immediately after calling // startSession may cause this test to fail to find the returned sessionId. // @tags: [does_not_support_stepdowns] // Basic tests for the $listSessions {allUsers: true } aggregation stage. (function() {     'use strict' ;     load( 'jstests/aggregation/extras/utils.js' );     const admin = db.getSiblingDB( "admin" );     const config = db.getSiblingDB( "config" );     const pipeline = [{ '$listSessions' : {allUsers: true }}];     function listSessions() {         return config.system.sessions.aggregate(pipeline);     }     function listSessionsWithFilter(filter) {         return config.system.sessions.aggregate([{ '$listSessions' : {allUsers: true }}, {$match: filter}]);     }     // Get current log level.     let originalLogLevel = assert .commandWorked(admin.setLogLevel(1)).was.verbosity;     try {         // Start a new session and capture its sessionId.         const myid = assert .commandWorked(admin.runCommand({startSession: 1})).id.id;         assert (myid !== undefined);         assert .commandWorked(admin.runCommand({refreshLogicalSessionCacheNow: 1}));         // Ensure that the cache now contains the session and is visible by admin.         assert .soon(function() {             const resultArray = listSessions().toArray();             if (resultArray.length < 1) {                 return false ;             }             const resultArrayMine = resultArray                                         .map(function(sess) {                                             return sess._id.id;                                         })                                         .filter(function(id) {                                             return 0 == bsonWoCompare({x: id}, {x: myid});                                         });             return resultArrayMine.length == 1;         }, "Failed to locate session in collection" );         const sessionList = listSessionsWithFilter({_id: "non_existent" }).toArray();         assert .eq(0, sessionList.length, tojson(sessionList));         // Make sure pipelining other collections fail.         assertErrorCode(admin.system.collections, pipeline, ErrorCodes.InvalidNamespace);     } finally {         admin.setLogLevel(originalLogLevel);     } })();