ドロワーメニュー表示時に、 背景が横スクロールしてしまう

Question

前提・実現したいこと

スマホ実機で見ると、
モバイル時のドロワーメニュー表示時に、
背景が横スクロールしてしまう
（ドロワーと背景が一緒にスライドします）

ドロワーメニューの表示にpushyというjqueryプラグインを使用しております。
» Pushy – Off-Canvas Navigation Menu

問題のサイトはこちらです
★弊社サイト

該当のソースコード

ドロワーメニュー部分のみですがHTML

<nav class="pushy pushy-left">
    <div class="pushy-content">
        <ul>
            <li class="pushy-link"><a href="https://store.shopping.yahoo.co.jp/exmail/"><img src="../img/logo_sp.png" class="offcanvas-logo" alt="ロゴ"></a></li>
            <li class="pushy-link"><a href="https://store.shopping.yahoo.co.jp/exmail/guide.html">お支払い方法/配送/返品</a></a></li>
            <li class="pushy-link"><a href="https://store.shopping.yahoo.co.jp/exmail/info.html" ><i class="fas fa-building fa-fw "></i>会社概要</a></li>
            <li class="pushy-link"><a href="https://talk.shopping.yahoo.co.jp/contact/exmail#" ><i class="fas fa-envelope fa-fw"></i>お問い合わせ</a></li>
        </ul>
    </div>
</nav>

.pushy {
    z-index: 10000;
    background: #fff;
    width: 300px;
}

.pushy-left{
    transform: translate3d(-300px,0,0);
}

.pushy-open-left #container,
.pushy-open-left .push {
    transform: translate3d(300px, 0, 0);
}

.pushy-right {
    transform: translate3d(300px, 0, 0);
}

.pushy-open-right #container,
.pushy-open-right .push {
    transform: translate3d(-300px, 0, 0);
}

pushy.js

/*! Pushy - v1.3.0 - 2019-6-25
* Pushy is a responsive off-canvas navigation menu using CSS transforms & transitions.
* https://github.com/christophery/pushy/
* by Christopher Yee */

(function ($) {
	var pushy = $('.pushy'), //menu css class
		body = $('body'),
		push = $('.push'), //css class to add pushy capability
		pushyLeft = 'pushy-left', //css class for left menu position
		pushyOpenLeft = 'pushy-open-left', //css class when menu is open (left position)
		pushyOpenRight = 'pushy-open-right', //css class when menu is open (right position)
		siteOverlay = $('.site-overlay'), //site overlay
		menuLinkFocus = $(pushy.data('focus')), //focus on link when menu is open
		menuSpeed = 200, //jQuery fallback menu speed
		menuWidth = pushy.width() + 'px', //jQuery fallback menu width
		submenuClass = '.pushy-submenu',
		submenuOpenClass = 'pushy-submenu-open',
		submenuClosedClass = 'pushy-submenu-closed',
		submenu = $(submenuClass);

	//check if menu-btn-class data attribute exists
	if( typeof pushy.data('menu-btn-class') !== 'undefined' ){
		var menuBtnClass = pushy.data('menu-btn-class'); //take user defined menu button CSS class
	}else{
		var menuBtnClass = '.menu-btn'; //set default menu button CSS class
	}

	//css classes to toggle the menu
	var menuBtn = $(menuBtnClass + ', .pushy-link');

	//css class to focus when menu is closed w/ esc key
	var menuBtnFocus = $(menuBtnClass);
	
    // check if container-selector data attribute exists
    var containerSelector = '#container';
    if (typeof pushy.data('container-selector') !== 'undefined') {
        containerSelector = pushy.data('container-selector');
    }
    var container = $(containerSelector);
		

	//close menu w/ esc key
	$(document).keyup(function(e) {
		//check if esc key is pressed
		if (e.keyCode == 27) {

			//check if menu is open
			if( body.hasClass(pushyOpenLeft) || body.hasClass(pushyOpenRight) ){
				if(cssTransforms3d){
					closePushy(); //close pushy
				}else{
					closePushyFallback();
					opened = false; //set menu state
				}
				
				//focus on menu button after menu is closed
				if(menuBtnFocus){
					menuBtnFocus.focus();
				}
				
			}

		}   
	});

	function togglePushy(){
		//add class to body based on menu position
		if( pushy.hasClass(pushyLeft) ){
			body.toggleClass(pushyOpenLeft);
		}else{
			body.toggleClass(pushyOpenRight);
		}

		//focus on link in menu after css transition ends
		if(menuLinkFocus){
			pushy.one('transitionend', function() {
				menuLinkFocus.focus();
			});
		}
		
	}

	function closePushy(){
		if( pushy.hasClass(pushyLeft) ){
			body.removeClass(pushyOpenLeft);
		}else{
			body.removeClass(pushyOpenRight);
		}
	}

	function openPushyFallback(){
		//animate menu position based on CSS class
		if( pushy.hasClass(pushyLeft) ){
			body.addClass(pushyOpenLeft);
			pushy.animate({left: "0px"}, menuSpeed);
			container.animate({left: menuWidth}, menuSpeed);
			//css class to add pushy capability
			push.animate({left: menuWidth}, menuSpeed);
		}else{
			body.addClass(pushyOpenRight);
			pushy.animate({right: '0px'}, menuSpeed);
			container.animate({right: menuWidth}, menuSpeed);
			push.animate({right: menuWidth}, menuSpeed);
		}

		//focus on link in menu
		if(menuLinkFocus){
			menuLinkFocus.focus();
		}
	}

	function closePushyFallback(){
		//animate menu position based on CSS class
		if( pushy.hasClass(pushyLeft) ){
			body.removeClass(pushyOpenLeft);
			pushy.animate({left: "-" + menuWidth}, menuSpeed);
			container.animate({left: "0px"}, menuSpeed);
			//css class to add pushy capability
			push.animate({left: "0px"}, menuSpeed);
		}else{
			body.removeClass(pushyOpenRight);
			pushy.animate({right: "-" + menuWidth}, menuSpeed);
			container.animate({right: "0px"}, menuSpeed);
			push.animate({right: "0px"}, menuSpeed);
		}
	}

	function toggleSubmenu(){
		//hide submenu by default
		$(submenuClass).addClass(submenuClosedClass);

		$(submenuClass).on('click', function(e){
	        var selected = $(this);

	        if( selected.hasClass(submenuClosedClass) ) {
				//hide same-level opened submenus
				selected.siblings(submenuClass).addClass(submenuClosedClass).removeClass(submenuOpenClass);
	            //show submenu
				selected.removeClass(submenuClosedClass).addClass(submenuOpenClass);
	        }else{
	            //hide submenu
	            selected.addClass(submenuClosedClass).removeClass(submenuOpenClass);
			}
			// prevent event to be triggered on parent
			e.stopPropagation();
	    });
	}

	//checks if 3d transforms are supported removing the modernizr dependency
	var cssTransforms3d = (function csstransforms3d(){
		var el = document.createElement('p'),
		supported = false,
		transforms = {
		    'webkitTransform':'-webkit-transform',
		    'OTransform':'-o-transform',
		    'msTransform':'-ms-transform',
		    'MozTransform':'-moz-transform',
		    'transform':'transform'
		};

		if(document.body !== null) {
			// Add it to the body to get the computed style
			document.body.insertBefore(el, null);

			for(var t in transforms){
			    if( el.style[t] !== undefined ){
			        el.style[t] = 'translate3d(1px,1px,1px)';
			        supported = window.getComputedStyle(el).getPropertyValue(transforms[t]);
			    }
			}

			document.body.removeChild(el);

			return (supported !== undefined && supported.length > 0 && supported !== "none");
		}else{
			return false;
		}
	})();

	if(cssTransforms3d){
		//toggle submenu
		toggleSubmenu();

		//toggle menu
		menuBtn.on('click', function(){
			togglePushy();
		});
		//close menu when clicking site overlay
		siteOverlay.on('click', function(){
			togglePushy();
		});
	}else{
		//add css class to body
		body.addClass('no-csstransforms3d');

		//hide menu by default
		if( pushy.hasClass(pushyLeft) ){
			pushy.css({left: "-" + menuWidth});
		}else{
			pushy.css({right: "-" + menuWidth});
		}

		//fixes IE scrollbar issue
		container.css({"overflow-x": "hidden"});

		//keep track of menu state (open/close)
		var opened = false;

		//toggle submenu
		toggleSubmenu();

		//toggle menu
		menuBtn.on('click', function(){
			if (opened) {
				closePushyFallback();
				opened = false;
			} else {
				openPushyFallback();
				opened = true;
			}
		});

		//close menu when clicking site overlay
		siteOverlay.on('click', function(){
			if (opened) {
				closePushyFallback();
				opened = false;
			} else {
				openPushyFallback();
				opened = true;
			}
		});
	}
}(jQuery));

試したこと

bodyタグにoverflow-x: hidden;をあてるという事を
やってみたのですが、問題の解消には至らずです。
（現状もそのままにしてあります。）

（***以下、関係ないかもしれませんが）
pushy内、widthはデフォルトの値から、300pxに広げています。
スマホヘッダーはposition: sticky;で固定

HTML等初心者です。
Windows7環境
当該サイトはYahooショッピング内となります。
未熟者の質問で申し訳ありません。
どうぞよろしくお願いいたします。

Comments

[makosankibu]

該当リンクが閲覧できません...
また、デベロッパーツールで何の要素がスクロールしているのか調べてみてください
一部のモバイル端末では、body,html要素にはoverflow:hiddenが有効にならないといった現象があるみたいです。
https://qiita.com/shge/items/d2ae44621ce2eec183e6