Some elements aren’t working

Hi,
I have a problem with elements that aren’t working on other sides than the homepage.
For example, user icon in navbar works just there: https://tech-week.cz/ .
It’s not working there for example: https://tech-week.cz/clanky-technologie/ .
In mobile, there are plenty more things in navbar, and its the same problem (working just on homepage).

Thank you for any advice

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