ap_invoices_interface_s.NEXTVAL is used to insert into ap_invoices interface

Does Oracle use a different sequence id for Invoice Id in AP invoices all?

ap_invoices_interface_s.NEXTVAL is used to populate the interface table. We have many operationg units having invoice interface being used. recently I am getting an issue:

Inetgration orchestratiion connects to oracle database in the custom schmea and in the orchestration flow they use the oracle sequence ap_invoices_interface_s.NEXTVAL to load invoices into a staging table. From the staging table we already have invoice id and we are just reading that invoice id and writing to the ap invoices interface table. We are getting unique constraint error. since we are using ap_invoices_interface_s.NEXTVAL we ae of the opinion we should not be getting this error.