We found the documentation in version 2.9 and 2.7 respectively.
Version 2.9 “This API endpoint returns data produced by the execution so far and closes the connection. If the execution has already completed, it will return all data produced by that execution.”
Version 2.7 : The API endpoints keep a long running connection open until the execution completes or the user closes the connection.
Once requested, the API endpoint returns any data which has been produced so far and after that, any new data as it becomes available.
Question: Does the API endpoints return the data and closes the connection automatically.
In the version 2.9.1, it immediately closes the connection.