The ERP system changes Payment by Invoice.

This is seen when downloading in PDF version, making use of the option that has the system. This is correct

What it follows is that the error is given when sending the mail, attach an incorrect version of the PDF.

I have a case, where a company still can not generate invoices, just vouchers. And everything works well when using this option, the only thing is that by sending the PDF by email, the payment word is changed to invoice, and that hurts us a lot legally.

(Image of the PDF received in the email)

Payment = Pago
Invoice = Factura

How can I solve this problem?