as you can see in the image, product list is not showing properly; altough there are more products in other pages, products list is not complete on a page, the last product on a page is not displayed.
There is no problem here! Your configuration is set to show 15 products per page. If you want to fill the last row, you need to set 16. Unfortunately when you open the store on devices with smaller screens and the products per row number is reduces there is no guarantee that you will have all rows filled. The only safe number here is 12 as it is divided to 4, 3 and 2.