User is attempting to connect to GlobalProtect. When attempted to connect to GlobalProtect the application appeared to stay loading and displayed "connecting..." but you would not prompt to sign in.
After restarting the device and attempting to sign into Globalprotect, the login prompt for CAS still does not appear.
GlobalProtect VPN for Desktop
Uninstall Globalprotect from the device and reinstalled it to resolve this matter. If using a Mac device, uninstalling Globalprotect will require using the installer and selecting the uninstall option listed in KB0016156