No inertial scrolling on iPhone

I found this problem on the site, and it is only present on the iPhone. If you try to scroll the page down with your finger, by swiping and releasing it from the screen on andriod, the page will scroll down for some more time, as if by inertia. On the iPhone, everything stops immediately. Moreover, to scroll, you need to drive straight with your finger with effort. Who can tell you what, maybe faced with this? You can view the site here: http://myiconskin.sopteh.beget.tech/

UPD: There is a scroll event:

$(document).ready(function(){
var $menu = $('#logo');
var $menufix = $('#logo_fix');
$('body').scroll(function(){
        if ( $(this).scrollTop() > 1 && $menu.hasClass('normal') && $menufix.hasClass('hide') ){
                $menu.removeClass('normal').addClass('hide');
                $menufix.removeClass('hide').addClass('normal');
        }
        else if($(this).scrollTop() <= 1 && $menu.hasClass('hide') && $menufix.hasClass('normal')) {
                $menu.removeClass('hide').addClass('normal');
                $menufix.removeClass('normal').addClass('hide');
        }
});

});