Jetpack – Square Tiles

Can anyone tell me what is going on with my gallery?

https://www.thelovelystars.com/home-tour/

I am using the “square tiles” feature, but thumbnails have oriented in a strange pattern. I can’t seem to find this replicated anywhere else. I have ensured that the number of images I am using is divisible by 3, so as not to mess up the alignment of the gallery. But still, it shows up in this strange pattern. Any ideas?

Thank you!