Apex domains cannot have CNAME records.
Question and response
Question
dig resilans.se. NS
Answer
resilans.se. 5 NS ns1.resilans.se.
resilans.se. 5 NS ns3.resilans.se.
resilans.se. 5 NS ns.cafax.se.
Authority
The response has no authority records.
Additional
ns.cafax.se. 5 A 192.71.228.17
ns1.resilans.se. 5 A 194.14.3.53
ns3.resilans.se. 5 A 194.71.2.53
ns.cafax.se. 5 AAAA 2001:6b0:302:0:0:0:0:17
ns1.resilans.se. 5 AAAA 2a01:280:1:0:0:0:0:53
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0