Epic name is not removed if Epic Issue type is change to another issue type

Summary

• Epic name should only be applicable to Epic Issue Type (based on the default custom field configuration context)
  
• However, if an issue is change from Epic issue type to lets say, a bug issue type, the issue name value under epic name is not removed/deleted. Which leads to confusion if user search in issue navigator. This also reflects in the database.

Environment

• JIRA Software

Steps to Reproduce

1. Create a new issue in Scrum Project
2. Set the issue type as an Epic
3. Set an Epic Name to it
   
4. Go to issue navigator, and search for the issue, you will see the Epic Name is shown correctly
5. Go back to the issue, change to issue type as Bug
6. You will see the Epic Name will be hidden in the issue page
   

Expected Results

• Going to issue navigator, the Epic Name should be empty

Actual Results

• Epic Name is showing for the issue
  
• Should not be right as a Bug issue type should not have an Epic Name

Notes

• This is reflected in database as well
• I've notice that for Epic Link, the field is updated to correct value (to be deleted) if issue type is change from Any Issue Type > _Epic Issue Type

Workaround

• none