Products per page & sorting system faulty after installing megashop template

Greetings,
im new to zen cart and i have to make some changes to a clients site installing a product per page filter and a sorting by module. The template im using is megashop. As for the sorting system . for some reason in some categories it sorts my products as requested. e.g. Product name - Product name-Desc etc. but for other categories it does not do anything. Also i've tried to import a product per page function that i found on the forum with no luck what so ever. I really don't know anything about zen cart and im trying my best to find a solution with your help. My local url is : http://eudatahost.com/heliland/catalog/

can anyone help me?

Thanks in advance

If you switch your template to "Responsive Classic", or just "Classic Contemporary Green", I suspect the sort will work fine, as well as probably the custom product-per-page setting you said you added.

I think the template package you installed has aggressively altered original PHP files and original functionality in ways that break how the admin configuration settings normally work, and how other normal functionality works. It's also possible that your custom template has also overwritten some original Zen Cart files and related to these features and therefore even switching to original templates may not even work right unless the files are reset.