Layout elements visibility on mobile/desktop

Hi,
I’m having trouble to manage my visibility of layout elements and color sections on mobile/desktop.
I create 2 layout elements or color sections, for one I set visibility on large and medium screens and for other on small and very small screens. When I go and test it on mobile screens I can see both. I’ve purged alla caches, gone incognito but nothing.
This is the page where I tried it: http://www.know-how.it/contatti/, but I’ve eliminated the second color section. Let me know if you want me to replicate the problem or you could do it yourself as I left the login details in pvt.

Thanks,
Anita