The info you provided is rather bare, so not much to give any clue.
To start with, please check whether this is the regular Chrome web browser or the mini web browser from Android captive portal detection. If the latter, you could try permitting connections to the URL site that used to perform this detection. If the former, please check the URL in the address bar to ensure it's that of your ISE BYOD portal and then check the html source (e.g. by following the instructions at How to view the HTML source code of a web page.
If you still need help from this community, please provide more info, such as the device vendor, the model, and the exact Android OS release.
