If I understand your issue correctly, the issue is that admins that are also moderators are not listed under the heading “Our Moderators” on the /about page?
If so, I don’t think it’s a bug, rather a feature to avoid duplicate avatars on the page.
If you click on the avatar of any admin that is also a moderator, does it show the little moderator shield beside their name on their user card or summary page, or is that the issue you’re reporting?
Example from the meta:
(I couldn’t find a place to sign up on your site, so I can’t confirm it there, and instead ask you here)