Get "not found" on full product page, QuickView works

Site URL: https://lobster-clover-mbgd.squarespace.com/

I am in a trial period - store is https://lobster-clover-mbgd.squarespace.com/ password "barley".

Enter the site, click Shop (top nav), then Preserves. Scroll down to the Summary block, "Queen of Hearts Raspberry Preserve". Hover over the picture, click Quick View. See that this shows the product. Now click "View full item" (or click on the product name in the category window). The result is a 404. Why?

Now 

Solved. The products "belonged" to a disabled Store page, part of my attempt to not use the standard Store page but add pages with my own content. It turns out there's a better way to do this - multiple Store pages.