Caption Overlay stopped working

Using the pro thumbnail grid on this page. It used to show the title and description when moused over, but just recently stopped working and I can’t figure out why. I have “enable caption overlay” in the settings set to “yes”. Any ideas why it would stop working? I switched to a default theme and disabled all plugins and the captions still do not show up on mouseover. Thanks!

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