Have you tried registering your Kiwi on sdr.hu using a domain name only to get a message in the Kiwi log (or the sdr.hu tab of the admin page) like:
Mon Jul 3 04:55:14 2017 0:00:38 .... sdr.hu registration: "ERROR (your IP does not match URL, 22.214.171.124 != 2003:80:ad1e:1900:b2d5:1234:5678:abcd)"
Then please try again when your Kiwi updates to at least release v1.100.
This problem occurs when your connection to the Internet supports both IPv4 and IPv6 addressing. sdr.hu has recently been moved to a server that also supports IPv6 addressing. So the registration information from your Kiwi is delivered to sdr.hu as an IPv6 packet. When your domain name is translated (e.g. kiwisdr.my_domain.com) it should have an IPv4 address. But may or may not have an IPv6 address. sdr.hu apparently doesn't handle all possible situations, and in the example above is incorrectly trying to compare an IPv4 against an IPv6 address. For security reasons sdr.hu requires that the ip from your domain name matches the ip of the registration packet.
In v1.100 the Kiwi registration information is forced to be sent on an IPv4 packet.