Portfolio Breaks Apart Need Help

Hey everyone,

I’ve been having this huge problem for past two weeks that I cant solve for the life of me i’ve spent hours n hours researching how and the owner of this premade theme won’t respond :(. If you see the page it’s a portfolio page set up with a grid of 4 but it breaks up around the 3rd row i cant figure out why! Heres url to the picture.

Let me know if you would like to see the coding since I cant give the URL since there is a landing page over the site