"Data cannot be retrieved due to an unexpected error." when viewing Jira Issue macro

Issue Summary

A Jira Service Desk customer that is a licensed user in Confluence but not Jira and Jira Service Desk, is prompted with jData cannot be retrieved due to an unexpected error. when viewing a Confluence page that has a Jira Issue macro.

In Confluence anonymous access is enabled and in Jira the project has Anyone on the web under Browse Projects 

Steps to Reproduce

1. Setup Confluence, Jira Software, and Jira Service Desk
2. Create a project in the Jira Service Desk
3. Create a customer in Jira to have access to the Jira Service Desk project portal (e.g. /servicedesk/customer/portal/1) but not to the actual Jira and Jira Service Desk application
4. Create the same user in Confluence
5. Enable Anonymous access in Confluence
6. Enable Anyone on the web permission under Browse Projects for the Jira project
7. Create a Jira Issue macro pointing to the Jira Project to a Confluence page
8. Login to Confluence as the user in step 3 and view the page

Expected Results

User able view the issues since anonymous access has been granted on both sides. Just like how an anoymous user can view the issues

Note

Anonymous user is able to view the Jira Issue macro

Actual Results

Workaround

Change the connection type from OAuth (impersonation) to OAuth on both Jira and Confluence.

If the Jira issue macro doesn't load, clicking on Refresh should do the trick