Adding an Epic ID via Edit Screen's Issue Link field results in epic link custom field population

Summary

As part of Backbone Sync App configuration, the epic ID is linked via edit issue screen's issue link field. This results in the epic link custom field to be populated.

Steps to Reproduce

1. Edit an issue (click Edit button)
2. Add the epic ID in the Issue Link field
3. Save
4. Do a Get Issue REST call to the edited issue

Expected Results

The epic link custom field should not be populated.

Actual Results

The epic link custom field got the value placed on the Issue Link field.

Workaround

Instead of using the edit issue screen to add the issue link, use "..." > Link