The following command has high chances reproducing the error: buildscripts/resmoke.py run --suites=replica_sets_kill_primary_jscore_passthrough BF-29978.js --userFriendlyOutput=resmoke.txt --additionalFeatureFlags featureFlagQuerySettings ... where BF-29978.js is as follows: import {assertDropAndRecreateCollection} from "jstests/libs/collection_drop_recreate.js" ; import {QuerySettingsUtils} from "jstests/libs/query_settings_utils.js" ; const coll = assertDropAndRecreateCollection(db, jsTestName()); const qsutils = new QuerySettingsUtils(db, coll.getName()); const querySettingsQuery = qsutils.makeFindQueryInstance({filter: {a: 1, b: 1}, skip: 3}); const querySettingsSettingsA = { indexHints: {allowedIndexes: [ "a_1" ]} }; const querySettingsSettingsB = { indexHints: {allowedIndexes: [ "b_1" ]} }; for (let i = 0; i < 10000; ++i) { jsTest.log( "Iteration = " + i); assert .commandWorked( db.adminCommand({setQuerySettings: querySettingsQuery, settings: querySettingsSettingsA})); assert .commandWorked( db.adminCommand({setQuerySettings: querySettingsQuery, settings: querySettingsSettingsB})); }