So I have a current issue with Jira's automation. I think it's a Bug.
First we have Jira's normal "Subtask", and that when I created the automation for it all goes smooth and well, as so:

However, I have created another Subtasks issue type called "Test Cases" (with it's own workflow) and when both subtasks are created within the same story, the "related issue condition" within the automation rule always fails even when I use JQL within the "related issue condition" so that I can specify exactly "Subtasks" and not "Test Cases" Subtasks , Like so:
Please let me know if you can help me with this situation or if it's a current issue within Jira