It’s only a matter of whitelisting the web apps with the correct URL. Chances are that you have added a web app for the URL in the subdomain but you might not have whitelisted the main page.
Let’s say you wanted to have a web app of the URL https://www.hexnode.com/forums/ and you have whitelisted the app in the Kiosk mode. While browsing, you may go back to the portal home hexnode.com and you may run into the error “you do not have the privileges to view this page” To avoid that, you can add another web app for the homepage https://www.hexnode.com/ then, whitelist this in the Kiosk mode, but this time you hide the app as well. This way, the home page will be accessible while navigating to home from the web app but it won’t be available as a standalone web app for the user.
Here are a couple of guides that may come in handy.