.NET 5.0 on Linux fails to connect to MongoDB 4.0 Atlas

Unhandled exception. System.TimeoutException: A timeout occurred after 30000ms selecting a server using CompositeServerSelector{ Selectors = MongoDB.Driver.MongoClient+AreSessionsSupportedServerSelector, LatencyLimitingServerSelector{ AllowedLatencyRange = 00:00:00.0150000 } }. Client view of cluster state is { ClusterId : "1", ConnectionMode : "ReplicaSet", Type : "ReplicaSet", State : "Disconnected", Servers : [{ ServerId: "{ ClusterId : 1, EndPoint : "Unspecified/mongodb40tlstest-shard-00-00.ebdql.mongodb.net:27017" }", EndPoint: "Unspecified/mongodb40tlstest-shard-00-00.ebdql.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.IO.IOException:  Received an unexpected EOF or 0 bytes from the transport stream.

... stack trace ...