Menu – works different on the home page than on subpages

I am using the Astra/Sierra theme.
In the “top Menu” of the page, I set the text color:
– black for Normal,
– yellow for Hover,
– yellow for Active.

The colors change correctly when the page is a subpage.
But if I set this page (or any other subpage) as home – the menu stops working as I would like.

How does it look like?
1) If the color yellow is set as Active – then all texts in the menu are yellow all the time. This means that you cannot see the “Hover” action.
2) If I change Active to black color – then you can see the “Hover” effect (text under the cursor is yellow), but you cannot see the effect of Active (text is black, as set).

Links for examples:
ad 2) subpage – with black, yellow, black = https://eng.sitemode.pl/home-test/
ad 2) home page – with black, yellow, black = https://eng.sitemode.pl/

Perhaps this is a problem of using anchors on a OnePage type page?
The anchors are made into sections (e.g. O nas = About Us) and the menu (/#About, /#Onas) directs to those anchors.

Is it possible to set this up correctly and how?

PS
Additional surprise – when you select a word from the menu and the page automatically scrolls to the selected section, the word in the menu gets a thin black rectangular frame. But I do not set such an effect for the “Active” variant. So why is this happening?

The page I need help with: [log in to see the link]