javascript - Why doesn't document.addEventListener('load', function) work in a greasemonkey script?

Question

It doesn't give an error, and I put a console.log('loaded userscript wifi-autologin'), the console.log works, but the intended effect of the document.addEventListener doesn't happen. After doing a bit more debugging, making it print that the addEventListener was called, I discovered that it wasn't being called.

Source of script:

// ==UserScript==
// @name        wifi-autologin
// @namespace   lf-ns
// @description Hopefully autologins to a captive portal
// @include     *://1.1.1.1/*
// @version     1
// @run-at document-end
// ==/UserScript==

document.addEventListener('load', submitAction);

Answer 1

Apparently, document.addEventListener() is unreliable, and hence, my error. Use window.addEventListener() with the same parameters, instead.