Connecting to a meteor.com hosted server with a third party client

I’m working on a Meteor/DDP client written in Swift. The code works well when I test it against a server deployed with mupx. However, when I test it against a server deployed on Meteor.com, I frequently have difficulty with the web socket connection. It works erratically, sometimes connecting, sometimes not. Both connections and errors seem to come in groups.

Specifically, it frequently fails to upgrade the connection to a web socket connection, returning a status code of 200 instead of 101.

I’m wondering if anyone has any experience with this here?