assinatura de certificado openssl: linha de assunto não copiada

Quando crio CSR, tenho a linha de assunto especificada.

$ openssl req -in csr -noout -text
...
Certificate Request:
    Data:
        Version: 1 (0x0)
        Subject: CN = 12345-67890, serialNumber = 67890, 1.3.5.7.9.24.6.8 = 1234
...

$ openssl ca -verbose -config signer.cnf -in csr -out output.crt
...
Certificate Request:
    Data:
        Version: 1 (0x0)
        Subject: CN = 12345-67890, serialNumber = 67890, 1.3.5.7.9.24.6.8 = 1234
...
Check that the request matches the signature
Signature ok
The Subject's Distinguished Name is as follows
commonName        :ASN.1 12:'12345-67890'
serialNumber      :PRINTABLE:'67890'
1.3.5.7.9.24.6.8  :ASN.1 12:'1234'
Everything appears to be ok, creating and signing the certificate
Successfully added extensions from config
The subject name appears to be ok, checking data base for clashes
Certificate is to be certified until Jun  1 16:48:27 2025 GMT (365 days)
Sign the certificate? [y/n]:

Mas quando verifico output.crt, a linha de assunto está vazia "Assunto:".

Abaixo está a configuração "signer.cnf".

[ ca ]
default_ca = my_ca

[ my_ca ]
dir = .
certs = $dir
new_certs_dir = $dir
database = index.txt
serial = serial
private_key = ...
certificate = ...
default_days = 365
policy = my_policy
x509_extensions = my_extensions
copy_extensions = copy

[ my_extensions ]
basicConstraints = CA:FALSE
keyUsage = digitalSignature, keyEncipherment

[ my_policy ]