Javascript 当我的手指未在ipad屏幕上释放时，航路点JS未启动

我不知道发生了什么，但直到我在Ipad屏幕上松开手指，waypoint js才会触发。在iphone中，一切都很好。但在Ipad中，动画直到我在屏幕上松开手指才开始运行

$('div.fullwidthgrid').waypoint(function(direction) {
        if (direction === 'down') {
            $("img#logo").animate({
                left: $("div.head-wid").width() / 2 - 28
            }, 100);
            $('img#logo').css('position', 'relative');
            $('.menu-mobile-btn').css("visibility", "visible");
            $('#main-header').css('width', '100%');

            $('.logo-titl').addClass('logo-title2');
            $('span#burger-red').addClass('filter-menu3');
            $('span#burger-red').removeClass('filter-menu');
            $('span#burger-red').removeClass('filter-menu2');
            $('p#mobmenu').addClass('menu-mobil2');
            $('p#mobmenu').removeClass('menu-mobil');
        } else {
            $('.menu-mobile-btn').css("visibility", "hidden");
            $("#logo").animate({
                left: 0
            }, 0);
            $('#logo').css("position", "relative");
            $('.tick-udp').removeClass('center-u');
            $('.logo-titl').removeClass('logo-title2');
            $('span#burger-red').addClass('filter-menu');
            $('span#burger-red').removeClass('filter-menu3');
            $('p#mobmenu').addClass('menu-mobil');
            $('p#mobmenu').removeClass('menu-mobil2');
        }
    }, {
       context:".et-fixed-header"

    });