I am using Studio 3T.

am not sure what is going on with "mongo" shell, but it is very slow.

As an example, create a query against a collection that has a filter against indexed field:

db.getCollection("Profile").find({

    locationCountry: "GB",

    uid: {$in: [ ...... ]}

}

the array $in has 22k elements,

in mongo shell the query never finishes, or at least I was not going to wait after +10 minutes.

when I use "legacy shell", it is expected behaviour and more like it was in Robo 3T which finishes in 10-15 seconds.