On the Old Issue View, a Subtask can be created under an Epic

Summary

On the New Issue View, Jira doesn't allow users to create a subtask under an epic but on the Old Issue View, you can create it:

Steps to Reproduce

1. Create an Epic
2. Access this Epic in the Old Issue View
3. Click on More button(. . .) on the top right
4. Click on Sub task

Expected Results

• Jira should not allow to create sub task under an Epic

Actual Results

• Jira allow a user to create a sub task on the old issue view