Insert command on a servless instance (Mongo Shell 4.9.0) breaking-serverless-1-shard-00-01(mongos-4.9.0-rc0)[mongos] testing> show collections breaking-serverless-1-shard-00-01(mongos-4.9.0-rc0)[mongos] testing> db[ "hello" ].insertOne({}) uncaught exception: TypeError: db.hello.insertOne is not a function : @(shell):1:1 Insert command on a local instance (Mongo Shell 4.2) MacBook-Pro-130(mongod-4.2.1) testing> show collections MacBook-Pro-130(mongod-4.2.1) testing> db[ "hello" ].insertOne({}) { "acknowledged" : true , "insertedId" : ObjectId( "6074a28f20a52b4a6c924d97" ) }