CMS Items do not organize themselves properly

I am creating an online store for my organization, and I have it set to show 6 CMS items per row. Most of the rows show 6 items like they should, but there is a few lines that don’t have any other CMS items on them. For example, I can see 6 items on the first row of the collections list. The second row has 6 items as well. The third row, however, randomly only shows 1 item and its at the end of the row too. The fourth row has 6 items. The fifth has the same problem as the third. Why is this happening and is there anything I can do to fix it?

I have included a picture of the current website as well as a link to one of the pages where this is happening: click here