Publishes IPv6 but doesn't answer on it — worse than having none.
Website over IPv6 edk9services.com has an AAAA record, but nothing answered on ports 443 or 80. IPv6 visitors wait for a timeout before falling back to IPv4.
✗ 2a07:7800::155 no answer
broken
www over IPv6 www.edk9services.com has an AAAA record and answers on it.
✓ 2a07:7800::155 answers · 443
yes
Mail servers (MX) have IPv6 None of the mail servers has an AAAA record.
mx.stackmail.com ✗
no
Nameservers have IPv6 No nameserver has an AAAA record — an IPv6-only resolver can't reach this domain's DNS.
Fix or remove the AAAA record for edk9services.com Something published an IPv6 address but nothing answers on it, so IPv6 visitors wait for a timeout first. Either make the server listen on IPv6 (and allow ports 443/80 through its firewall), or delete the AAAA record until it does.
Mail servers without IPv6 mx.stackmail.com has no AAAA record, so mail from IPv6-only servers can't reach it directly. If a provider runs your mail, that's their setting; if you run it, add AAAA records for these hosts.
Nameservers without IPv6 ns1.ibrave.host, ns2.ibrave.host, ns3.ibrave.host, ns4.ibrave.host 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.