What could be the reason for this behavior when scrolling on iphone?

Question

css

The page scrolls as if it has already ended, and only then the content appears. I did not find anything hanging on the scroll event in the scripts (I did not develop the site).

The problem is also that there is really nowhere to test, the problem is only with the customer, and only the manager contacts the customer.

Answer 1

Wangyu that this is some ancient iPhone ... Which was presented to the director by "good friends".
You can test with:
1) Desktop debugger Chrome + - Safari. There is an emulator in DevTools, though it's not 100%.
2) iPhone emulator in MacOS.
3) Actually "Ayfun". Since you're doing layout...
4) Services-emulators.
By the way, there is an old-school method "on an ancient iPhone" - install Windows Safari. Yes, yes, exactly the old one that Apple scored.

Answer 2

On Bitrix.. Veselukha...
Judging by the scripts

function scrollbarWidth() {
        var $inner = $('<div style="width:100%; height:200px;"></div>'),
            $outer = $('<div style="width:200px;height:150px;position:absolute;top:0;left:0;visibility:hidden;overflow:hidden;"></div>').append($inner),
            inner = $inner[0],
            outer = $outer[0];

        $('body').append(outer);
        var width1 = inner.offsetWidth;
        $outer.css('overflow', 'scroll');
        var width2 = outer.clientWidth;
        $outer.remove();

        return (width1 - width2);
    };

There are influences on the scoll and not only

http://www.eurogazstroy.ru/bitrix/cache/js/s1/euro/template_0edfc10eb291a57b138ae73bdf2fb41e/template_0edfc10eb291a57b138ae73bdf2fb41e.js?