HTTPS over IPv6· not part of the grade yet The certificate served over IPv6 at 2605:6f00:1234:211:1::26f isn't valid for ftp.lunarmania.com: ERR_TLS_CERT_ALTNAME_INVALID.
https://ftp.lunarmania.com/ via 2605:6f00:1234:211:1::26f· ERR_TLS_CERT_ALTNAME_INVALID
problem
What's keeping ftp.lunarmania.com from an A
The certificate served over IPv6 is wrong The certificate served over IPv6 at 2605:6f00:1234:211:1::26f isn't valid for ftp.lunarmania.com: ERR_TLS_CERT_ALTNAME_INVALID. Often the IPv6 address points at a different server (or an old one) than IPv4 does. Make sure 2605:6f00:1234:211:1::26f serves the same certificate as your IPv4 address.
Mail servers without IPv6 spam-fw01.lunarpages.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 power.websiteservername.net, tesseract.websiteservername.net 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.