Hi,
I dont think that SSO is enable in your system as you should not get any login page once you login on the portal.
Please recheck all the SSO config.
Please check the below two parameters in the backend.
login/accept_sso2_ticket 1
login/create_sso2_ticket 1
Certificate imported in strustsso2 in ACL and certificate list.
All the JCo configured properly.
and system landscape settings are ok.
Thanks
Rishi Abrol