If you are seeing problems then we recommend that you open a ticket with Speechmatics support: support@speechmatics.com. Please include the logging output from the container if you do open a ticket, and ideally enable verbose logging.
Verbose logging is enabled by running the container with the environment variable DEBUG set to true.
e.g.
docker run -e DEBUG=true speechmatics-docker-example.jfrog.io/rt-asr-transcriber-en:1.0.0
You should ensure, when using the config object in the StartRecognition message, that the JSON is correctly formatted.