2 Column View not displaying correctly

Hello Chris

I’ve used your terrific plugin on a number of projects, but just having something strange going on with my latest website. I have set the 2 Column Masonry Modern view on this page http://insideroom.bantergroup.com.au/testimonials/ but it only seems to display in 2 columns on page reload. When you first reach the page it displays in one column.

I’ve never seen this happen before, so not sure what to start checking. Any ideas what might be going on?

Regards
Melanie

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