Here is the docuentation overrides in Chrome, it seems to me a very useful feature in cases where you don't have access to the backend or you don't want to deploy.
I don't understand why it shows you: "Verificado por: No especificado"and me: "Verificado por: FNMT-RCM"if I check it with another tool I get ‘Issuer: FNMT-RCM’.https://www.sslshopper.com/ssl-checker.html#hostname=sp.seg-social.es
It works for me. Check the date, I see that the certificate is valid today.Not before Wed, 24 Jan 2024 09:52:23 GMTNot after Fri, 24 Jan 2025 09:52:23 GMT