Python Iris.CreateIRIS generates connection error

Hi, I'm trying to use the iris python package to create a connection to and Iris Health instance (Docker Container), but getting and error. I can login to the instance using the UI with the same uname/password but unable to create the python connection. Any suggestions?

conn = iris.connect("testserver",52222,"%SYS","username","password")

After executing this I get an exception trap
An error occurred: Invalid Message Count: expected: 1 got: 825110831