iirc this doesn't work in Firefox? or at least it doesn't work the same way as in Chrome. I developed a tiny home-cooked app[0] that depended on this behavior using desktop Chrome which then broke when I tried to use it on mobile Firefox. I then switched it to using

  document.getElementById

like I should have and everything worked fine. Like others in this thread, I recommend not relying on this behavior.

[0]: https://www.robinsloan.com/notes/home-cooked-app/