store content showing multiple times while browsing through ordered list

Sometimes (or perhaps all the time) when I try looking through multiple pages of content in the store, I start seeing some of it over and over. Any ideas what's happening or how to avoid this?

If it matters, usually what I'm doing is Shop > Sales and Promotions > DAZ Originals, then changing the "sort by" dropdown to price, then changing the number of items per page dropdown to 60, then after viewing the page, pressing the Next button at the bottom.

I'm not sure If I'm seeing repeats with the same price or in the same order; I wondered if perhaps prices or content were being shuffled around while I was browsing resulting in more content being added to the list, and the Next was going to the next page in the updated list instead of the original list or something.