HTML5 Drag'n'Drop - Not Working on iOS 12.1.2 (Safari and Chrome)

Background

I have a list that is sortable via drag and drop. It works perfectly on desktop browser, and on Chrome on Android. However, it didn't work at all on Safari and Chrome on iOS 12.1.2 (iPhone 8).

Current Code

See snippet below, and also for easy mobile testing: https://codepen.io/Kelderic/full/PXvjWp

var dragging = null;

document.addEventListener('dragstart', function(event) {
  var target = getLI(event.target);
  dragging = target;
  event.dataTransfer.setData('text/plain', null);
  event.dataTransfer.setDragImage(self.dragging, 0, 0);
});

document.addEventListener('dragover', function(event) {
  event.preventDefault();
  var target = getLI(event.target);
  var bounding = target.getBoundingClientRect()
  var offset = bounding.y + (bounding.height / 2);
  if (event.clientY - offset > 0) {
    target.style['border-bottom'] = 'solid 4px blue';
    target.style['border-top'] = '';
  } else {
    target.style['border-top'] = 'solid 4px blue';
    target.style['border-bottom'] = '';
  }
});

document.addEventListener('dragleave', function(event) {
  var target = getLI(event.target);
  target.style['border-bottom'] = '';
  target.style['border-top'] = '';
});

document.addEventListener('drop', function(event) {
  event.preventDefault();
  var target = getLI(event.target);
  if (target.style['border-bottom'] !== '') {
    target.style['border-bottom'] = '';
    target.parentNode.insertBefore(dragging, event.target.nextSibling);
  } else {
    target.style['border-top'] = '';
    target.parentNode.insertBefore(dragging, event.target);
  }
});

function getLI(target) {
  while (target.nodeName.toLowerCase() != 'li' && target.nodeName.toLowerCase() != 'body') {
    target = target.parentNode;
  }
  if (target.nodeName.toLowerCase() == 'body') {
    return false;
  } else {
    return target;
  }
}

ul.sorting {
  padding: 0;
  margin: 0;
  list-style: none;
  max-height: 300px;
  overflow-y: auto;
  box-shadow: inset 0 0 3px 1px rgba(0, 0, 0, 0.2);
}

ul.sorting li {
  padding: 10px;
  border-bottom: 1px solid black;
  user-select: none;
  cursor: move;
}

ul.sorting li:last-child {
  border-bottom: none;
}

<ul class="sorting">
  <li draggable="true" style="user-drag:element;">List Item 15</li>
  <li draggable="true" style="-webkit-user-drag:element;">List Item 2</li>
  <li draggable="true" style="-webkit-user-drag:element;">List Item 3</li>
  <li draggable="true" style="-webkit-user-drag:element;">List Item 4</li>
  <li draggable="true" style="-webkit-user-drag:element;">List Item 5</li>
  <li draggable="true" style="-webkit-user-drag:element;">List Item 6</li>
  <li draggable="true" style="-webkit-user-drag:element;">List Item 7</li>
  <li draggable="true" style="-webkit-user-drag:element;">List Item 8</li>
  <li draggable="true" style="-webkit-user-drag:element;">List Item 9</li>
  <li draggable="true" style="-webkit-user-drag:element;">List Item 10</li>
  <li draggable="true" style="-webkit-user-drag:element;">List Item 11</li>
  <li draggable="true" style="-webkit-user-drag:element;">List Item 12</li>
</ul>

Video of Behavior on iOS

https://imgur.com/a/I8hzPxC (Size is too large for direct embed)

Question

Why is this not working on iOS? I can't even get the dragstart event to fire. On Android Chrome, a longpress fires the drag start.

My fallback idea is to make a longpress using touchstart and touchend, then create my own absolutely positioned ghost element and drag it around manually. That is a lot of extra code when the drag* events should just work.

Am I missing something?

from HTML5 Drag'n'Drop - Not Working on iOS 12.1.2 (Safari and Chrome)