Superuser is not permitted to login
You didn't specify the LOGIN right:

ALTER ROLE portal WITH LOGIN;


If you use CREATE USER instead of CREATE ROLE the LOGIN right is granted automatically; otherwise you must specify it in the WITH clause of the CREATE statement.

Superusers do not inherently have the LOGIN right; a permissions check is still performed for superuser for this right. The reason for this is so that you can have a superuser role that you can SET ROLE to, but cannot be connected as directly.