What is causing this party site use error?

We're on Oracle EBS R12.2.10 and we have an interface program to create and update suppliers. When reactivating a inactive supplier, we're getting an error when updating the party site use table via the HZ_PARTY_SITE_V2PUB API. Here is the pertinent code:

SELECT  psu.party_site_id,

        psu.party_site_use_id,

        psu.object_version_number,

        psu.site_use_type

FROM hz_party_site_uses psu

WHERE psu.party_site_id = i_party_site_id

AND psu.site_use_type = 'PAY'

ORDER BY psu.party_site_id DESC;

...

l_psu_rec.status := p_status;
l_psu_rec.party_site_use_id := l_rec.party_site_use_id;