Client connecting to Greengrass error - AWS_IO_SOCKET_CONNECTION_REFUSED: socket connection refused

Hi, we are running Greengrass core within a docker container running in Ubuntu on WSL2. We can successfully run discovery. We are receiving an error when trying to test a client connection using "aws-iot-device-sdk-python-v2/samples/basic_discovery.py".

The error we are receiving is "Connection failed with exception AWS_IO_SOCKET_CONNECTION_REFUSED: socket connection refused. "

Any ideas on where to look to debug and resolve this issue?

Thanks