Code injection for bilingual site navigation

Hey,

could anyone help me with code injection issue? I'm using Version 7.0– Brine family (Impact template), as a bilingual site. I managed to use the navigation in each language with a page header code injection, which helps me to hide the other language navigation buttons. It was working fine, but I just discovered, that altough I shift from language 1 to language 2, the navigation remains language 1 (on mobile as well). I think the code is ok, because on squarespace it works fine (in editorial mode). Site is here: www.molton.hu

I use this code (in case of language 1):

<style>nav.Header-nav--secondary {
   display: none;
 }

  .Mobile-overlay-nav--secondary {
   display: none;
  }
</style>

After I refresh browser, the navigation shifts to the correct language.

What is the problem? Was there any kind of updates or changes in this template, which can cause this issue?

Thanks in advance

Daniel