Try this at home.

Reroute www.apple.com to a httpd on a RFC1916 address.

Make sure your iPhone resolves www.apple.com to the RFC1916 address where your httpd is listening.

Disable WiFi on your iPhone. Then enable it.

I was presented with a Log On HTML page as if I was a guest or at a public hostpot.

I was not be able to stay connected.

When I created the requisite /library/test/success.html page in the httpd's root folder, I was successful.

Why does the iPhone need to access www.apple.com in order to fucntion on a home LAN, that may or may not be connected to the Internet?