Issue creation from Portfolio plan does not create the Epic Link on the first step

Problem Definition

Currently, for stories - when we create stories, we set the epic-link in a second step, so any post functions that triggered before the epic link is set might fail if you are using the Epic link value for something else. The reason for this two-step process is that we use the Jira Core API to create the issue, and then we use the Jira Software API to set the epic link.

Suggested Solution

Enhance this feature so that the Epic link gets created in the first step by using JIRA Core API.

Note

This works fine if we create the issue from Create button from JIRA menu bar.