First item in gallery gird simple is always bigger?

Hey everyone! I've come across an issue that has left me very confused. I built this gallery for a client, and for some reason I can't understand, the first item of each row won't scale similarly to the rest of the items, always looking a bit bigger.

It was working before and I haven't changed a thing, so I'm lost as to what happened. I'm attaching a video below of the weird scaling effect.

URL: https://indigo-red-fw2y.squarespace.com/publications

No password is needed. 

Thank you so much for your help and guidance!