To reproduce outside of Mongosync: Launch and connect to v7.0 replica set (I used mlaunch) m 7.0.0 mlaunch --replicaset --nodes 3 mongosh mongodb: //localhost:27017,localhost:27018,localhost:27019 - You will need 2 mongosh for this repro. Create collection and index use test db.createCollection( "coll" ) db.coll.createIndex({x:1}) On mongosh 1, run the aggregation pipeline to retrieve the index in an infinite loop (replace collectionUUID with actual value) stages1 = [{ "$group" : Unknown macro: { "_id" }} }, { "$unwind" :{ "path" : "$catalogEntry" }}, { "$unwind" :{ "path" : "$catalogEntry.md.indexes" }}, { "$unset" : "catalogEntry.md.indexes.spec.ns" }, { "$match" :{ "catalogEntry.md.indexes.ready" : true }}, { "$set" : { "catalogEntry.md.indexes.spec.sparse" : { "$cond" : { " if " :Unknown macro: { "$eq" }, "then" : "$$REMOVE" , " else " : { "$toBool" : "$catalogEntry.md.indexes.spec.sparse" } } }, "catalogEntry.md.indexes.spec.expireAfterSeconds" : { "$cond" : { " if " :Unknown macro: { "$eq" }, "then" : "$$REMOVE" , " else " : { "$toInt" : "$catalogEntry.md.indexes.spec.expireAfterSeconds" } } }, "catalogEntry.md.indexes.spec.bits" : { "$cond" : { " if " :Unknown macro: { "$eq" }, "then" : "$$REMOVE" , " else " : { "$toInt" : "$catalogEntry.md.indexes.spec.bits" } } } } }, { "$group" : { "_id" : "$catalogEntry.md.indexes.spec.name" , "shards" :{ "$push" : "$catalogEntry.shard" }, "specs" : { "$push" : { "$objectToArray" : { "$ifNull" : [ "$catalogEntry.md.indexes.spec" , {}] } } }, "allShards" : { "$first" : "$allShards" } } }] stages2 = { "$project" : { "numShards" :{ "$size" : "$allShards" }, "missingFromShards" : { "$setDifference" : [ "$allShards" , "$shards" ] }, "spec" : { "$arrayToObject" :{ "$first" : "$specs" }}, "inconsistentOptions" : { "$setDifference" : [ { "$reduce" : { "input" : "$specs" , "initialValue" :{ "$arrayElemAt" : [ "$specs" , 0] }, "in" : { "$setUnion" : [ "$$value" , "$$ this " ] } } }, { "$reduce" : { "input" : "$specs" , "initialValue" :{ "$arrayElemAt" : [ "$specs" , 0] }, "in" : { "$setIntersection" : [ "$$value" , "$$ this " ] } } }] } } } res = db.runCommand({ "aggregate" : "coll" , "collectionUUID" : new UUID( "85c8ab7b-d107-4768-913e-19f0b107eb2a" ), "readConcern" : { "level" : "majority" , "afterClusterTime" : Timestamp({ t: 1693905823, i: 20 })}, cursor: {}, pipeline: [\{ "$listCatalog" : {}}].concat(stages1).concat([\{ "$match" : {_id: "x_1" } }]).concat([stages2])}).cursor.firstBatch.length while (res) { res = db.runCommand({ "aggregate" : "coll" , "collectionUUID" : new UUID( "85c8ab7b-d107-4768-913e-19f0b107eb2a" ), "readConcern" : { "level" : "majority" , "afterClusterTime" : Timestamp({ t: 1693905823, i: 20 })}, cursor: {}, pipeline: [\{ "$listCatalog" : {}}].concat(stages1).concat([\{ "$match" : {_id: "x_1" } }]).concat([stages2])}).cursor.firstBatch.length }  - On mongosh 2, rename the collection use test db.coll.renameCollection( "coll2" ) The infinite loop in mongosh 1 will exit. In v6.0.8, the infinite loop exits with a CollectionUUIDMismatch error as expected, but v.7.0.0, the infinite loop exits because the server returns an empty list of index.