SSL VPN Doesn't prompt for password change when reset from AD

Hello,

I was using fortiOs 5.0, I configured an SSL VPN With LDAP authentication for AD users. I configured

set password-expiry-warning enable

set password-renewal enable

and the Portal could prompt users to change there password when reset by an admin on the AD. But, ever since we upgraded to FortiOs 5.4 this feature doesn't work. Fortigate ssl VPN portal does not prompt users to change password, The portal just shows blank page. This is a critical issue for us, can anyone please help with this?