SEC_ERROR_UNKNOWN_ISSUER on Ubuntu server and Apache 2.4

I’m not linking directly to the live folder, but copying the files to it’s own directory.

The apache config is setup the same on both Ubuntu and Debian Apache:

SSLEngine On
SSLCertificateKeyFile /etc/ssl/privkey.pem
SSLCertificateFile /etc/ssl/fullchain.pem

Command used to renew open:

/root/letsencrypt/letsencrypt-auto certonly --standalone -d domain.com --standalone-supported-challenges tls-sni-01 --renew-by-default