This is a very specific issue as it only applies to IE11 under Windows 8.1. You can easily track the mouse position using following code snippet:
document.addEventListener('mouseout', function(e) {
console.log(e.clientY);
});
If you paste this in the console of any browser, you will see that it outputs a negative value whenever you move your mouse to the address bar / top of your screen.
But in IE11 under Windows 8.1 the event is never triggered when clientY
is supposedly holding negative values.
How can I detect a user moving out of the document when I cannot detect negative values?