Before applying the fix provided in this article, refer to:
This article was written using the following software for testing:
If we follow the steps provided in the articles mentioned previously, we will be configuring the hostname of the ProxySG as the virtual URL used for authentication. By default, Firefox does not allow automatic NTLM authentication to sites that are not FQDN, meaning that when we are redirected to this virtual URL, it will ask for credentials before it can successfully authenticate the user, as the browser will not recognize the name as an FQDN.
Change the default behavior of automatic authentication for non-fqdn sites.