Redirect after Captive Portal not redirecting

Does it redirect when you set "Redirect after captive portal" to "Original request"?

To test the redirection configuration, it is better to use a Windows host. Smartphones and the use of a CNA may ignore the last redirection after they gain internet access.

This cannot be resolved by your wireless environment. Although I hate on Apple and their lack of enterprise support, they really nailed it with the Captive Network Assistant. When an Apple device joins an open wireless network, it's attempts a simple HTTP GET in the background. If that GET is not successful, it launches a lightweight browser that will redirect to your captive portal.