If you create the unproxied application link in Confluence, the Whitelist entry for Jira will display the Display URL while it is actually pointing to the Application URL that the request is coming from.

Confluence administrator had to add a new entry with the same Display URL to resolve the issue accessing the link in the page header as it is rendered by the jira-metadata plugin that is going through the whitelisted Application URL. This causes the Whitelist to print the Display URL twice and cause confusion to the administrator who maintain the instance.

Therefore, it is best to display the correct whitelisted Application URL instead of Display URL when we create the unproxied application link in Confluence.

8/23 Update:
To clarify the workaround: add another Whitelist rule for <display URL>/* with a Type of Wildcard expression.