The menucard will use one parent category per column. If you use child categories then all those child categories will appear in that one column as well. To make it span over multiple columns, select more then one category on the menucard page in the back office and you’ll see that they’ll use more columns 🙂
If this doesn’t help, can you share a link to your website so I can take a look? Also, did you use our dummy content or did you add the content yourself?