Same with pale moon just displays it with the puny code instead of the unicode characters.
Firefox 52.0.2 here displays it as apple.com
So updated Firefox (which failed until I reran it) and then.. Still displays it as apple.com (Firefox 53.0)
OK, I read the linked article now and apparently you have to change a setting in Firefox in order to see the URL in punycode as Mozilla decided it is "not a bug".
Eg. about:config and set the "network.IDN_show_punycode" to true to avoid this trap.
Firefox 52.0.2 here displays it as apple.com So updated Firefox (which failed until I reran it) and then.. Still displays it as apple.com (Firefox 53.0)