CMS Masonry Grid_Issue on Firefox

Hi there, I’ve been doing the website for my architecture studio, and for the projects section we wanted to do a Pinterest like Masonry Grid with the CMS projects.
It works great on Chrome, but on Firefox it stacks the item vertically

Does anyone know how to fix this?

Here’s my read-only link
And it’s already live for some user testing if you rather check it here


Here is my site Read-Only: LINK
(how to share your site Read-Only link)