The data security will not get set for any user automatically unless some one specifically assigns it. Also, if the tables related to security are fiddled manually then the security might get assigned. There are 4 tables related to security that ...
If the security is assigned at Role level, then check if the equivalent security tables for Role is available in the Warehouse. If there are no tables created or wrong tables being created, then create required tables (e.g.: ADMIN_ROLE_STORE and ...