For Amigopod Web Login pages where an anonymous authentication is selected, the Pre-Authentication must be set to "Local". This will ensure that the username and password get sent to the controller
If Local pre-authentication is not enabled, the user will be redirected to the controller to authenticate but then will immediately go back to Amigopod with an "Access Denied" error. This is due to Amigopod sending the controller a blank password. The controller rejects captive portal authentication attempts without a password.