Thanks, now I see what's happening.

My first recommendation is that you upgrade. Many updates, including security fixes, have happened since that version. At a minimum, upgrade to the latest maintenance release for 23.3, and ideally to the latest release available:

• Latest release of LabKey Server

I can't reproduce this issue locally, so it's possible it's been fixed, and upgrading is all you'll need to do. Even readers should be able to see the display name of other users, though not other user details or group memberships.
If not, I believe the explanation is that these built-in lookups to user names are done on the "SiteUsers" table which is by design only accessible to site administrators. To display usernames to non-admins, you can edit the table metadata to make those lookups point to the project's "Users" table instead. Learn more about this in the documentation here:

• Show CreatedBy and/or ModifiedBy Fields to Users

As long as all you want to show is the username, assigning that other "See User and Group Details" role will not be necessary.

--Molly