Post Categories Not Visible in Admin

I am having a problem with post categories administration.

The problem seems to have presented itself after moving domains.

The site is on a Multisite install, the other sites do not have the same problem.

I can add new categories in the Admin menu but they do not display in the admin menu or as an option when creating or editing a post.

I can see older categories that were created some weeks ago, but not the new ones. New categories do not display when I search for them but I can view the page if I go directly to the edit page and manually change the the ID in the URL, ie: https://www.xyz.org/wp-admin/edit-tags.php?action=edit&taxonomy=category&tag_ID=26&post_type=post, the category appears and is editable.

I can see all categories in the database in the xx_2_terms table.

If I relate the post to a “missing” category, the post will not appear, if I relate the post to a “visible” category, the post will appear.

I’d appreciate any advice anyone has on this matter. Thank you.