A timeout occurred after 2999ms selecting a server using CompositeServerSelector{ Selectors = ReadPreferenceServerSelector{ ReadPreference = { Mode : Primary } }, LatencyLimitingServerSelector{ AllowedLatencyRange = 00:00:00.0150000 }, OperationsCountServerSelector }. Client view of cluster state is { ClusterId : "1", Type : "Unknown", State : "Disconnected", Servers : [{ ServerId: "{ ClusterId : 1, EndPoint : "Unspecified/localhost:27017" }", EndPoint: "Unspecified/localhost: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.Sockets.SocketException (111): Connection refused at MongoDB.Driver.Core.Misc.TaskExtensions.WaitTask(Task task, TimeSpan timeout, CancellationToken cancellationToken) at MongoDB.Driver.Core.Connections.TcpStreamFactory.Connect(Socket socket, EndPoint endPoint, CancellationToken cancellationToken) at MongoDB.Driver.Core.Connections.TcpStreamFactory.CreateStream(EndPoint endPoint, CancellationToken cancellationToken) at MongoDB.Driver.Core.Connections.BinaryConnection.OpenHelper(OperationContext operationContext) --- End of inner exception stack trace --- at MongoDB.Driver.Core.Connections.BinaryConnection.OpenHelper(OperationContext operationContext) at MongoDB.Driver.Core.Connections.BinaryConnection.Open(OperationContext operationContext) at MongoDB.Driver.Core.Servers.ServerMonitor.InitializeConnection(OperationContext operationContext) at MongoDB.Driver.Core.Servers.ServerMonitor.Heartbeat(CancellationToken cancellationToken)", LastHeartbeatTimestamp: "2026-08-17T05:18:51.8325441Z", LastUpdateTimestamp: "2026-08-17T05:18:51.8325444Z" }] }.