Masonry Card Template – Page not fully loading

Hi – I have set my website up with the masonry card template, set to display 3 columns. When the site initially loads, only the first column seems to display and there is a blank white space to the right of this until either I scroll down or refresh the page and then the other two columns will spring into position.

This issue is on laptop (desktop) running windows 10 and in Chrome and Firefox browsers.

I love the theme and template style, but don’t know what I am doing wrong or how to fix this issue. Any help would be very gratefully accepted.

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