Nameservers have IPv6 No nameserver has an AAAA record — an IPv6-only resolver can't reach this domain's DNS.
ns200.anycast.me ✗dns200.anycast.me ✗
no
HTTPS over IPv6· not part of the grade yet The certificate served over IPv6 at 2001:41d0:301:100:54:38:64:46 isn't valid for ftp.mining-dutch.nl: ERR_TLS_CERT_ALTNAME_INVALID.
https://ftp.mining-dutch.nl/ via 2001:41d0:301:100:54:38:64:46· ERR_TLS_CERT_ALTNAME_INVALID
problem
What's keeping ftp.mining-dutch.nl from an A
The certificate served over IPv6 is wrong The certificate served over IPv6 at 2001:41d0:301:100:54:38:64:46 isn't valid for ftp.mining-dutch.nl: ERR_TLS_CERT_ALTNAME_INVALID. Often the IPv6 address points at a different server (or an old one) than IPv4 does. Make sure 2001:41d0:301:100:54:38:64:46 serves the same certificate as your IPv4 address.
Mail servers without IPv6 mx0.mail.ovh.net, mx1.mail.ovh.net, mx2.mail.ovh.net have no AAAA record, so mail from IPv6-only servers can't reach them directly. If a provider runs your mail, that's their setting; if you run it, add AAAA records for these hosts.
Nameservers without IPv6 ns200.anycast.me, dns200.anycast.me all have no AAAA record, so a resolver that only speaks IPv6 can't look your domain up. Most DNS providers offer IPv6 nameservers; ask yours, or move DNS to one that does.