It's against almost all certificate standards for the certificate holder - Tesonet to allow an unrelated third party to use a certificate with their name on it.

It's against almost all certificate standards for the certificate holder - Tesonet to allow an unrelated third party to use a certificate with their name on it. Or for a third party (proton) to use a certificate that has another companies name on it. If you would like, I can pursue this issue further given what seems to be confirmation here of a certificate violation.