What is the problem?
In the message correlation documentation we state at the end of the paragraph that
In case of successful correlation, the correlated or newly created process instance is updated with the variables from the processVariables map.
In case of event subprocesses with message a start event and messages that are supposed to be correlated to and hand over their payload to the event subprocess scope, it is not clear enough that the recipient of those variables will rather be the parent execution than the event subprocess scope.
This occurred in SUPPORT-5580 as well as in the forum already.
What would be the expected behavior:
Have a clarifying notice or paragraph on event subprocesses in the message correlation documentation.
The event subprocess' message start event is treated as an intermediate message catch event of the parent process instance and not as a message start event, therefore no new process instance will be created for the event subprocess.