When you configure the IIS page to protect, the user enters the link in the browser that is not case matched to the page i.e. all lowercase, or camel cased in a different way you input into the plugin box then it fails to invoke the plugin which bypasses 2FA.
Release : VIP 1.0
To troubleshoot redirect URLs to lowercase in Microsoft IIS login page when integrating with Symantec VIP, you can follow these steps: