I recently updated a couple certs on our ISE server. I applied the same cert to the default portal policy as well as EAP Authentication. We went from an OV cert to an EV cert which required an intermediate cert to be installed to the ISE server. I am not having any problems with anything except the Guest Portal on Android.
What is happening is the Certificate chain is not complete on the android devices. All laptops are listing it as valid cert as they are listing the root and intermediate certs. I can manually install the intermediate cert on my android devices and have it show as valid, however that should not be needed as it is installed on the ISE server.
On top of that problem, we are recieving the portal redirect page (connectivitycheck.gstatic.com) and no portal. The only way I have been able to get around this is by clicking "connect as is" and open chrome; I then navigate to "connectivitycheck.gstatic.com". Then I am redirected to the correct Guest Portal.
Any help is appreciated