"Custom Domain" column empty under the "Sites" menu?

Logged in as Super Admin, when I go to the "Sites" menu, there is a column called "Custom Domain" which is empty even though I do have a couple of domains successfully mapped to their sub sites.

Isn't the mapped domain supposed to show up in that column?

I checked the database, and the wp_domain_mapping table does exist now... and the mapped domain does show up in that table under the "domain" column.

So, am I missing a setting, or is something funky going on?