Order menu items won't change

Hello,

I have built a website and am trying to change the order of the main menu on the front end. I have changed the order of the menu items in the backend (layout > site structure), but on the FE the menu items stay the same... I refreshed the page, cleared the browser cache and the Contao cache, but nothing happens.
Does anybody know the answer?

Thanks.

The problem is already fixed...