In the attached image you can see that I have a post archive, using the Looper Consumer to display the category posts. I have it set in a 3-column layout with a max of 21 posts to consume (also configured in WordPress settings).
On an archive page like https://smarthernews.com/category/law/, you can see that if there aren’t exactly three posts the columns jump to two or even one column and it fills the space.
How can I force this to stay to one column only?