Unable to access the CI (component interface) with the technical user in PeopleSoft

We have created a custom CI using the component HR_HOME_MAILING. Following that the  CI (component interface) is assigned to a permission list and provided full access to all the methods ( cancel, get, find, save ).

Adding to that, the respective component and pages are assigned full access in the same permission list. Ran the security batch and portal sync for the permissions to reflect the recent changes for sure.

Now we use this CI in the API handler code for a REST service. While we run the test using the user who has emplid tagged the service is working perfectly.