Category page shows list of all items in that category. Of course. I would very much have exactly the same display under each product at their individual product pages. (Hope I managed to explain...)
How can I fix that?
You should not modify core files .. if you would like to donate a cup of coffee I will write it in a modification for you.
Spinning Social : Links : Menus : Payments : Socials : Ads : Screen Backgrounds : Galleries : Headers : Banners : Promos
Maybe I explained poorly. Sorry. No, that suggestion means I have to edit each product and add products one by one. Not really doable. I mean to add the list of all category items under the details/image, etc on each individual product page. Look at a category page, you'll see all stuff listed (on a laptop or desktop they're in rows and four columns). Then, when you go to any of those products own pages, it's empty below (unless you've added a module to layout or something). I would like that empty space under the product to look exactly as the category page you were looking at before. Hope I did better now...
My Modules by Category extension may be an easy way to deal with it. Simply add the latest module to the bottom of the page and set the limit to a number high enough to include all the products that might be in the category.