Captive portal not popping up on iOS?

[jedahan]

I checked that /cna-portal was doing a 302 redirect, but seems it wasn't enough for my iPhone.

I then tried adding dhcp-option=114,http://occupy.here/index.php to dnsmasq, as described in https://developer.apple.com/news/?id=q78sq5rv but that didn't seem to do anything.

Open to other ideas.