We have a test Atlas database up and running.

We can connect to it using Mongo Shell and list the collections from the database successfully.

However, when we try and connect using C# (running the following code):

var settings = MongoClientSettings.FromConnectionString("mongodb+srv://menadmin:<our password here>@cluster0.k2loi.mongodb.net/MAP?retryWrites=true&w=majority");
var client = new MongoClient(settings);
var dbList = client.ListDatabases().ToList();

Where <our password here> is replaced by our password. Running this code gives this error:

System.TimeoutException: 'A timeout occurred after 30000ms selecting a server using CompositeServerSelector{ Selectors = MongoDB.Driver.MongoClient+AreSessionsSupportedServerSelector, LatencyLimitingServerSelector

{ AllowedLatencyRange = 00:00:00.0150000 }

, OperationsCountServerSelector }. Client view of cluster state is { ClusterId : "1", ConnectionMode : "ReplicaSet", Type : "ReplicaSet", State : "Disconnected", Servers : [{ ServerId: "

{ ClusterId : 1, EndPoint : "Unspecified/cluster0-shard-00-00.k2loi.mongodb.net:27017" }

", EndPoint: "Unspecified/cluster0-shard-00-00.k2loi.mongodb.net:27017", ReasonChanged: "Heartbeat", State: "Disconnected", ServerVersion: , TopologyVersion: , Type: "Unknown", HeartbeatException: "MongoDB.Driver.MongoConnectionException: An exception occurred while opening a connection to the server.
---> System.Net.Internals.SocketExceptionFactory+ExtendedSocketException (10060): A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. 52.31.23.157:27017

We are using version 2.14.1 of the C# Mongo drivers. It also fails using version 2.10.4 with the same error. We have also tried the code from a .NET framework application and a .NET core application with the same result.

Do you have any idea what the issue could be?