Ap_vendor_pub_pkg.update_vendor_site API is not updating a field

Question

Hello
I want to update the Calculate Tax field on the supplier site level.
I am using the ap_vendor_pub_pkg.update_vendor_site API to update the ap_supplier_sites_all.auto_tax_calc_flag field. But the API does not update the field. I want to change the value of the auto_tax_calc_flag from 'L' or 'N' to 'Y'
I am running the API as a concurrent request. Thus the org_id should be set when you use the relevant responsibility
Below is my code. Am I missing a parameter? The API does complete successfully. The ap_supplier_sites_all table does show as updated when you look at the last_update_date field. But the auto_tax_calc_flag value does not change
Any ideas why the api is not updating
create or replace procedure apps3_mtnaol.mtn_update_supp_sites(errbuf in out varchar2, retcode in out number) is
v_error_message varchar2(3000);
l_vendor_site_rec ap_vendor_pub_pkg.r_vendor_site_rec_type;
l_return_status varchar2(1000);
l_msg_count number;
l_msg_data varchar2(2000);
l_msg_dummy varchar2(3000);
l_output varchar2(3000);
l_vendor_name varchar2(3000);
l_vendor_number varchar2(3000);
l_vendor_site_code varchar2(3000);
v_vendor_site_code varchar2(3000);
v_vendor_site_id number;
v_party_site_id number;
l_remmitance_email varchar2(2000);
v_party_id number;
v_party_site_name varchar2(3000);
v_ext_payee_rec iby_disbursement_setup_pub.external_payee_rec_type;
cursor c_1
is
select segment1
,vendor_name
,vendor_id
--,vendor_site_id --vendor_site_id from org_id 22970
,vendor_site_code
,vendor_type_lookup_code
,org_id
,party_id
,party_site_id
from mtn_supplier_site_22970
where 1 = 1
and segment1 = '661699';
begin
for rec in c_1 loop
select assa.vendor_site_id -- get vendor_site_id from org_id 5001
,assa.party_site_id
into v_vendor_site_id
,v_party_site_id
from ap_supplier_sites_all assa
where 1=1
and org_id = 5001
and assa.vendor_id = rec.vendor_id
and vendor_site_code = rec.vendor_site_code;
select party_id
,party_site_name
into v_party_id
,v_party_site_name
from hz_party_sites
where 1=1
and party_site_id = v_party_site_id;
fnd_msg_pub.delete_msg(null);
fnd_msg_pub.initialize();
l_return_status := '';
l_msg_count := '';
l_msg_data := '';
l_vendor_site_rec.vendor_site_code := rec.vendor_site_code;
l_vendor_site_rec.auto_tax_calc_flag := 'Y'; --calculate_tax field that needs to be set to Yes
l_vendor_site_rec.org_id := 5001;
l_vendor_site_rec.vendor_id := rec.vendor_id;
l_vendor_site_rec.party_site_id := v_party_site_id;
l_vendor_site_rec.party_site_name := v_party_site_name;
v_ext_payee_rec.payee_party_id := v_party_id;
v_ext_payee_rec.supplier_site_id := v_vendor_site_id;
v_ext_payee_rec.payee_party_site_id := v_party_site_id;
v_ext_payee_rec.payer_org_id := 5001;
ap_vendor_pub_pkg.update_vendor_site(p_api_version => 1.0,
p_init_msg_list => fnd_api.g_true,
p_commit => fnd_api.g_true,
p_validation_level => fnd_api.g_valid_level_full,
x_return_status => l_return_status,
x_msg_count => l_msg_count,
x_msg_data => l_msg_data,
p_vendor_site_rec => l_vendor_site_rec,
p_vendor_site_id => v_vendor_site_id
l_output := '';
if l_return_status <> 'S' then
for i in 1..l_msg_count loop
fnd_msg_pub.get(i, fnd_api.g_false, l_msg_data, l_msg_dummy);
l_output := l_output || (to_char(i) ||': '|| substr(l_msg_data,1,250));
fnd_file.put_line(fnd_file.output, 'Unsuccessful Update:'||l_return_status||': '||l_msg_count||', '||l_output);
fnd_file.put_line(fnd_file.output, 'Vendor Number: ' ||l_vendor_number);
fnd_file.put_line(fnd_file.output, 'Vendor Name: ' ||l_vendor_name);
fnd_file.put_line(fnd_file.output, 'Vendor Site Code: ' ||l_vendor_site_code);
fnd_file.put_line(fnd_file.output, 'Calculate Tax: ' ||l_vendor_site_rec.auto_tax_calc_flag);
end loop;
else
fnd_file.put_line(fnd_file.output, 'Successful Update:' ||l_return_status||': '||l_msg_count||', '||l_output);
fnd_file.put_line(fnd_file.output, 'Vendor Number: ' ||l_vendor_number);
fnd_file.put_line(fnd_file.output, 'Vendor Name: ' ||l_vendor_name);
fnd_file.put_line(fnd_file.output, 'Vendor Site Code: ' ||l_vendor_site_code);
fnd_file.put_line(fnd_file.output, 'Calculate Tax: ' ||l_vendor_site_rec.auto_tax_calc_flag);
end if;
commit;
end loop;
exception when others then v_error_message:= 'Other error: ' || SQLERRM;
fnd_file.put_line(fnd_file.output, 'Error Message: '||v_error_message);
fnd_file.put_line(fnd_file.log,'***************************************************************************');
fnd_file.put_line(fnd_file.log, 'Other error: ' || SQLERRM);
fnd_file.put_line(fnd_file.log,'***************************************************************************');
end;
/

Answer 1

Yes the API works outside my code.
I have used this exact same API to successfully update other fields on the ap_supplier_sites_all table like hold_unmatched_invoices_flag, match_option, pay_group_lookup_code, pay_date_basis_lookup_code, and always_take_disc_flag fields