Apex domains cannot have CNAME records.
Question and response
Question
dig arkaden.se. NS
Answer
arkaden.se. 5 NS ns2.ipv6dns.se.
arkaden.se. 5 NS ns1.ipv6dns.se.
arkaden.se. 5 NS ns1.arkaden.se.
arkaden.se. 5 NS anycast.interlan.nu.
Authority
The response has no authority records.
Additional
ns1.arkaden.se. 5 A 83.68.239.130
ns1.ipv6dns.se. 5 A 192.71.21.35
ns2.ipv6dns.se. 1 A 185.42.137.98
ns2.ipv6dns.se. 1 A 194.58.192.32
anycast.interlan.nu. 1 A 194.58.198.32
ns1.ipv6dns.se. 5 AAAA 2001:67c:2448:10:0:0:0:53
ns2.ipv6dns.se. 1 AAAA 2a01:3f0:400:0:0:0:0:32
ns2.ipv6dns.se. 1 AAAA 2a01:3f1:32:0:0:0:0:53
anycast.interlan.nu. 1 AAAA 2a01:3f1:3032:0:0:0:0:53
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0