Why is my position:sticky not working on iOS?

Question

I'm in the process of coding a sticky notification bar seated at the bottom of a mobile screen. I want the bar to be stuck at the bottom of the users screen until the user has reached the scroll position of where the bar is actually positioned in the code (which is just before the footer of the page). I have pretty much copied the "doctor" example from this page: https://alligator.io/css/position-sticky/ My problem is: On my page, the bar works fine when using Android Devices or when simulating a mobile device by adjusting the Browser width on my Desktop Computer. However, on iOS, the bar is not sticky, i.e. it just sits at its position and doesn't stick to the bottom of the screen until reached. This applies to both Safari and Google Chrome. The weird thing is: On the previously mentioned alligator.io page, it works just fine on my iOS device.

I suspect this is some kind of Webkit problem having to do with the code surrounding the bar, but I cannot isolate it. I have tried debugging by adjusting my code as far as possible to the example from alligator.io, but I cannot get it to work. I have also tried looking for any overflow:auto in parent elements - without success. I have been trying to fix this for several hours and am sick and tired of the problem and could use another pair of eyes to help me find what I'm overlooking.

#jobalarm_mobile {
    display: table;
    font-size: 18px;
    width: 100%;
    height: 40px;
    background: #ff8400;
    color: white;
    font-weight: 400;
    text-align: center;
    position: -webkit-sticky;
    position: sticky;
    bottom: -50px;
    align-self: flex-end;
}

<a href="#" class="jobAlertToggle">
    <div id="jobalarm_mobile">
        <i class="fa fa-bell"></i>
        <span>Jobalarm aktivieren</span>
        <label class="switch">
            <input type="checkbox">
            <span class="slider round"></span>
        </label>
    </div>
</a>

You can visit the live page I am working on at (hidden on request of the customer, please contact me privately). Simply start any (suggested) search and the bar will pop up (or not, if you are using iOS...) Thanks in advance for your help.

Answer 1

I feel like an idiot for answering my own question, but I figured out what is causing the problem. I hope this will help developers facing the same problem because I could not find anywhere defining this behavior.

As you can see, in my code, there is a wrapper (specifically a link) around the element, on which I use my position:sticky:

<a href="#" class="jobAlertToggle">
<div id="jobalarm_mobile">
    <i class="fa fa-bell"></i>
    <span>Jobalarm aktivieren</span>
    <label class="switch">
        <input type="checkbox">
        <span class="slider round"></span>
    </label>
</div>
</a>

For some reason, this is not a problem for Chrome or Firefox on Desktop as well as Android, as they seem to ignore this container, probably because it doesn't define any positioning behavior. This is why it works on other devices. However, iOS does not ignore the container and therefor positions the div relative to its parent container, which is the link. After removing the link for test purposes, it worked on all devices.

Answer 2

This is the real answer

position: -webkit-sticky;
position: -moz-sticky;
position: -o-sticky;
position: -ms-sticky;
position: sticky;

and works!!!