Why does mobil Safari have horizontal scrolling when overflow-x: hidden?

Question

safari

There is a site diffi.ru, it implements multi-level mobile navigation prntscr.com/e4chka which works on js and сss transform: translateX. The menu appears by shifting the body to the right, you can hide the menu back only:
1. By pressing a special button prntscr.com/e4cire
2. Tap on an empty area of ​​the body prntscr.com/e4ciyg
Swipe on the menu itself cannot be swiped prntscr.com/e4cjbg
Problem :
All this works fine on chrome and Android, but on mobile safari on iphone, horizontal scrolling appears, which allows you to swipe the menu with a swipe plus everything twitches terribly.
What has been done:
Worth overflow-x: hidden; width:100%; on the tag but safari ignores this style.
Code links:
JS diffi.ru/bitrix/templates/Cornery/js/mlpushmenu.js
CSS: diffi.ru/bitrix/templates/Cornery/template_styles.css
How to fix this problem?