Issue with active menu when it's a category

Hi,
I get an issue with my menu items.
I have both pages and categories in the menu (using wp_nav_menu) but I have trouble when I want to highlight the current categories items.
What I would like is to have only the parent category highlighted when the user in on this category and not its child.
Same thing, when an user is on a child category or in a single item of a category, the other childs and the parent are also highlighted!

I tried current class like “current-page-ancestor” and other but I can’t manage to do what I’d like.
Here’s an URL to see what I mean.
The “portfolio” item of the navigation is a category.

Please I really need help on it.
I’m stuck on it for hours.

Regards