Post functions carry out any additional processing required after a transition is executed. Always add any post functions after "Create Issue Originally" default post function. If post function is added before the "Create Issue Originally", the workflow does not execute the post function since no issue is created.
We have a Create Issue post function with the Create on transition app that processes when users transition issues from "Open" to "In Draft". Create Issue allows you to create one or more issues when the post function is processed after a workflow transition step.
It is recommended to add the post functions after "Create Issue Originally" default post function.