Javascript cannot capture ESC keyup event in Vivaldi browser

I am developing a Javascript library (AnyList) in which users may press the ESC key to abort editing an input field. This is implemented by catching the ESC keyup event (using jQuery):

inp_elem.on("keyup", init_opt, $.proxy(this._processKeyup,this));
...
$.any.DataView.prototype._processKeyup = function (event)
{
  if (event.preventDefault)
    event.preventDefault();
  if (event.type == "keyup" && event.which == 27) { // ESC. In Vivaldi, we never get here.
    ...
  }
  ...

This works fine in Firefox, Edge, Chrome, etc. but not in the Vivaldi browser - the _processKeyup method is never called.

Vivaldi uses the ESC key to stop the loading of a html page but so do other browsers, and even if I delete the ESC keyboard mapping (there is an option for this in Vivaldi), I am not able to catch the ESC event in my Javascript.

Can anybody help? I really like the Vivaldi browser and would like to see it succeed, but this behaviour breaks my script unneccessarily and is quite annoying.

It seems that Vivaldi browser is catching the keyUp event, so you'd better to use keyDown event instead.

A working solution could be something like that:

elem.onkeydown = function (event) {   
    if (event.type === "keydown" && event.key === 'Escape') {
        alert('esc - everywhere'); 
        }
}