Hello, the signatures made on a PDF with the identification card of Spain (DNIe) the product does not manage to validate it correctly since the hierarchy that signs the OCSP response has been modified and instead of being signed by a subordinate the root itself does.

The OCSP response is signed by the following certificate:

https://www.dnie.es/descargas/certificados/Ocsp_Responder_AV_DNIE_FNMT_AC_RAIZ_DNIE_2_0320 18.zip

This certificate is issued directly by the Root Authority:
https://www.dnie.es/ZIP/ACRAIZ-DNIE2.zip

Why does the PDF indicate "certificate not valid for use?

There is a test set available to make a valid signature and another with certificate revoked at this link:
https://www.dnie.es/descargas/certificados/Set_Certificados_Pruebas.rar

Thank you very much