Admin Comments Fields Missing/Misaligned

I run a few dozen WP sites and most have similar configurations. One site now does not display the Comments appropriately in the Admin section for Comments. The Admin Comments Headings should be Author, Comment, In Response To, and, Submitted On. Standard stuff.

This site has Author (data is blank), In Response To (which displays Author info), and Submitted On (displays the post name, comment count), but no Comment heading is displayed (and, as above, data that does display is displayed under the wrong heading).

I checked the Admin Page code and the actual Comment is in the code but does not display on the admin page (does display on the post), which makes me think this could be a CSS problem. I used phpMyAdmin to check the database and all looks good (comments where comments should be).

I did a WP reinstall. No change. No new plugins have been installed or updated and this site’s configuration is identical to a dozen other sites that do not have a similar issue. I removed and reinstalled plugins one after the other. No change.

What’s wrong? Any ideas?

The page I need help with: [log in to see the link]