Hello,
I opened a support case in the CA Support page, and i received the next answer:
[–] Created By: Diego Lombardia On: 15.08.2018 14:55
Hello Adolfo, I have checked our knowledge base and found that we do not have the option to choose any other signature algorithm for the CSR file than the default sha512WithRSAEncryption. Please let us know if you have any further doubt. Regards, Diego Lombardia CA Technologies Technical Support
As well the customer told us that the CSR are signed in SHA512 algorithm.
So, the customer takes the decision of to sign the CSR with another CA, and the case it was solved.
Thank You.
Adolfo.