Issue Summary

Sub-tasks can be created under Epic via CSV import

Steps to Reproduce

• In the CSV file, update the Parent ID column of a Sub-task Issue type to an Epic Issue's Issue ID. 
• Import this file on a project from the External system Import> CSV
• The Sub-task will be created under the Epic Issue.
• After this, other Sub-tasks can also be created from inline. 

Expected Results

The Sub-tasks should not be allowed to be created under Epic issue types, adhering to the Issue hierarchy structure in Jira. 

Actual Results

The Sub-tasks can be imported as child issues under Epic, furthermore, this makes way for additional Sub-tasks to be created by the inline Issue creation option from within Epic. 

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available