Hello Gaurav,
Not sure if this has been solved already or not, however I can suggest you the following. The authorization values which you have mentioned are the appropriate ones
GRFN_API
ACTVT: 01, 02, 03
GRC_DATPAT: ROLES & ROLES_PC
GRC_ENTITY: ORGUNIT
GRC_SUBTYP: *
Make sure that these values are also maintained in the role which you're assigning in the front end. In your case I think you are using SAP_GRC_SPC_SOX_CTL_OWNER under ORGUNIT however if you haven't modified the values of the standard role you will notice that this role only contains 03 activity for GRC_ENTITY:ORGUNIT so probably that is the issue.
Probably you can create a custom role based on the standard one, add one new node with the values mentioned, maintain it under SPRO and do the front end assignment; that should do the trick
Regards