Error when updating Organization Costing using API hr_organization_api.update_organization

I am trying to update the Organization Costing information using the API - hr_organization_api.update_organization.

I am only trying to update the first 2 segments.

I am getting the following error -

ORA-20001: FLEX-NULL REQUIRED SEGMENT: N, SEGMENT_NAME, Activity, N, ERRMSG, The following required field does not have a value: Activity

The error message is referring to the 3rd segment of the Costing KFF which is called Activity. None of the segments are mandatory in our setup.

Any idea why I am getting this error ?

Script is given below -

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declare

l_organization_id number;

l_cost_allocation_keyflex_id number;