Issue Summary

Access key users can be @mentioned in comments but are not highlighted when the comment is saved and rendered

Steps to Reproduce

1. In a PR comment, using @ search for an access key user and add them
2. save the comment and view the unhighlighted user

Expected Results

Access key user should not show up when searching for users in comments.

Actual Results

Access key users do show up in comments, but are then not highlighted once the comment is saved.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available