Only one category working

Greetings,

I am using the plugin WooCommerce Price by Country . I want to Increase by Fixed price in category level. So I have three categories: A, B and C (all three of these are on the same level in the category tree). All of this categories have “Unique” price by country and the same two zones for increase price: Europe and non-Europe.

All products within the A category work fine, but the others in the categories B and C do not work at all when actually the three of them are, like I said, “Unique”, same zones, same “increase by Fixed Price”, the only different thing is the amount of increase price. Can you help me out with this please.

WordPress version: 5.4.4
WooCommerce version: 4.6.1
Price by Country plugin version: 1.0.1

What I’ve tried:
1. Deactivate and delete plugin
2. Take any product from B and C and move it to the A category, this works just fine, so it is not the products, so A category works, B and C does not.
3. Create a “test” category and put it in some B and C products, this does not work.
4. Take an A category product and change it to B or C, doesn’t work, but when I return it to A category it does work.