I have an application running Twisted Python 3.7, and we're trying to convert it to run against Atlas and not our own managed MongoDB.

Our local MongoDB has no authentication so it was pretty straight forward. But moving to Atlas we now need to use TLS for the connection and I keep on getting TxMongo lost connection to MongoDB. after connecting.

My connection is of type mongodb srv://.../?authSource=$external&authMechanism=MONGODB-X509&retryWrites=true&w=majority and I have the certificate and private key files, of course.

I tried using txmongo example from