[Plugin: cbnet Different Posts Per Page] Plugin seems not to be working

Hello,

I use your plugin in a blog.
I made 2 categories
1perpage with 1 articles a page
2perpage with 2 articles a page.

The first article I gave the category 1perpage.
The second article I gave the category 2perpage.

But when you goto this url: https://test.tamarawobben.nl/2005/04/
you will see that both articles are shown on the first page.

What went wrong here ?

Roelof

https://www.ads-software.com/extend/plugins/cbnet-different-posts-per-page/