Hi @immunity,
Remove the AAAA record for www.starenio.gr from your DNS server and try again. The other option is to configure the ipv6 address for your domain and the web server correctly to serve your domain using ipv6 too.
Note: 2a01:4f8:c0c:fa1:: is not a valid ipv6 address, is the subnet 2a01:4f8:c0c:fa1::/64 assigned to you by Hetzner.
Cheers,
sahsanu