first thing to test is to clear your browser caches on the mobile device. If the issue persists, try viewing the site in a Private/Incognito browser. And if its still a problem, connect your phone to a different network and check again in a private browser.
If theres still a problem, share the link to the site in the Private Information field and ill take a look.
thanks for your answer.
i cleared the cache and i used a private incongnito browser but i still have the same problem.
The menu on the mobile website: home, services, about, tutorials, contact
the menu on the desktop website which is correct: home, plugins, hosting, service, tutorials, kontakt