Collections show random number of items

Hi I have defined four collections and added books to each collection. When I use the shortcodes on the front end the site randomly loads different numbers of books in each collection. On one page load it might load 2 books in the business collection, then I refresh and it loads 5, then another refresh and it loads 3. The books shown are not consistent either, everything seems to be happening randomly. I disabled caching and tried on two sites already, same issues.

https://www.ads-software.com/plugins/amazonsimpleadmin/