Post Grid post only vertical

I'm using Post Grid to display my blog posts, and there used to be 3 posts horizontal next to each other. For some reason my blogs are now posted vertically below each other, spreading the posts full screen. When putting the grid in a smaller section, the images get smaller but they're still vertically displayed. Changing image size doesn't work, the size stays the same, the image only gets blurry.

I have only been updating my website, posting new blogs, I haven't changed the blog home page in a while. I stumbled across this by accident, so I don't think it's something I manually changed.