Hello,
That’s very strange because we have checked on different mobile devices and don’t see problem http://prntscr.com/o8zje4
Also, if we use emulation also everything is ok https://gyazo.com/e697c2db90f9aa6bfc62b90e1e170d5e
Do you have the problem with the menu for all the pages or maybe just for 1 specific page? Provide link to that page.
Regards