When we are instantiating a request with workflow it is successfully getting instantiated from CA Identity Portal it is showing correctly in Status, however when we go to Approvals in CA Identity Portal with approver login we can't see the approval tasks. We do see all workflow items successfully in CA Identity Manager UI.
The resolution was to re-create the IM connector in CA Identity Portal. We did so by renaming the connector ID, which deleted the existing one and created a new one. Subsequently, a new webservice and Admin role were created in IM with the same new name. Then we removed the old webservice (with the old name) from CA Identity Manager as well, and confirmed the new Admin role was created and the old one automatically removed.