Changes in filename for customer_invoices from v1 to v2

When creating a customer_invoice through the API in v1 the generated filename would be like : Facture-XXX.pdf.
This behaviour is still present when creating through pennylane directly, but when migrating to v2 when I generate the invoices through the API it is now :
Invoice-XXX.pdf
the locale seems to be correctly set to fr_FR so I don't understand why I get this behaviour.
I see that I can control the generated filename for the invoice, but since it contains the pennylane internal number I can't use it since I don't know it beforehand.