要約

In the Jira comment section, the comment author name is seen along with a "Not a request participant" tag.

診断

The user for whom the "Not a request participant" tag is seen is not an active user (i.e. does not have access to the site) or does not have "Browse Projects" permission

ソリューション

This is expected behavior. As per the current design in the Jira cloud, when a user who previously had access to the Jira issue and added comments is revoked access to the project/site, then the comment author name is seen with the tag "Not a request participant". If the user is granted site access or project access, then the comment author name is seen without the aforementioned tag.