I have a task and Epic. When I proceed with a task automatically the Epic status progresses. (execute transition in Epic).
You should enter a pair of post-functions in the transition of task's workflow used for making task's proceed (e.g. "Proceed Task"). These post-functions are:
Insert Copy a parsed text to a field post-function with the following configuration:
I'm supposing that transition "Start Progress" in epic's workflow is used for making epics progress.
Insert Write field on linked issues or sub-tasks post-function with the following configuration:
Once configured, "Proceed Task" transition in task's workflow will look like this: