Editing Issue Using Edit Button Triggers Issue Assigned Event Instead of Issue Updated if We Make Changes In Assignee Field as Well

Summary

If you click the edit button and make multiple changes, not all of these changes are reflected in the triggered email. An example is when changing the description, assignee and adding an attachment, it triggers the issue assigned email instead of issue updated

Environment

• JIRA Version 6.4
• JIRA Version 7.3.3

Steps to Reproduce

1. Create an issue
2. Click Edit button for the created issue and changes assignee, description and other fields
3. Wait for JIRA to send notification

Expected Results

Issue Updated notification is send as multiple field is editted.

Actual Results

Issue assigned event is triggered and only changes for this field is notified while other field are ignored.

Notes

This behaviour only happens when assignee field is editted together with other field.

Workaround

Edit Assignee using the Assign Button and other fields using Edit Button