Hello team,
As per Support ticket GHS-4488:

Hi Atlassian Support,

In the Rapid Board Kanban "Work" mode, when we move a story/parent that has sub-tasks through the workflow, we'd like to be able to have the option of moving the subtasks to the same workflow status, as long as the subtask workflow and parent workflows support that status.

Right now, when we move a story/parent to "In Progress", the subtasks just sit in the "Open" category.

Thanks,
Bob

Please let us know the possibility of implementing this feature request.
Thanks,