Showing all subcategories on homepage makes blank white areas among categories

I am using Page Builder for my homepage in Directory Theme with Teslia child theme.

On my homepage, I am using Category Style 2 and showing images for categories, 3 per row. I am also showing all of my subcategories under the categories. Some categories have only a few subcategories and some have many.

If there are too many subcategories, the next row of categories is displayed unevenly with only 1 or 2 categories per row leaving blank white blocks of space. See attached image. I understand it is supposed to work this way and it would work properly if I showed fewer subcategories or no subcategories. But I want to show all subcategories.

I would like to force every row of categories to start down far enough on the page that there is space for all 3 categories in the row, without leaving big blank white chunks. See attached image. Is there some way I can manipulate this with CSS?

Thanks!

Sorry for the double uploads of the files below. I made a mistake and can’t see any the option of deleting the 2 extra files.