Internal mention notification is triggered to customer accounts

Issue Summary

When mentioning a customer that already interacted with the ticket (added a comment) in the JSM portal, an internal mention notification is being triggered to the portal customer.

Steps to Reproduce

1. As an internal user (agent/collaborator), access a ticket via the portal
2. Mention the customer (reporter/request participant) on the request (again, via portal)

Expected Results

The mention notification is similar to customer notifications an all links from the message redirects the customer to the JSM portal.

Actual Results

The notification is similar to an internal notification and the View Issue link redirects the customer to Jira internal view, returning an access permission error.

Workaround

Instead of mentioning the user, make sure you have the Public comment added customer notification enabled so that the user receives the comment notification.