Hi there!
Is it possible to block duplication of subtasks within the parent issue when changing its status backward / forward? Please have a look at the below;
When: Issue Transitioned
From: Draft
To: In Review
Then: Create a new (sub-tasks)
In: My_Project
However, once I get back from step "In Review" to "Draft" and then again from "Draft" to "In Review" - subtasks duplicate and arise again.
I hope that the solution is pretty easy for advanced users and I can count on your help. 