Apex domains cannot have CNAME records.
Question and response
Question
dig itgarden.net. NS
Answer
itgarden.net. 5 NS ns1.itgarden.se.
itgarden.net. 5 NS ns2.itgarden.se.
itgarden.net. 5 NS ns3.itgarden.se.
Authority
The response has no authority records.
Additional
ns1.itgarden.se. 5 A 193.138.74.75
ns2.itgarden.se. 5 A 18.159.9.125
ns3.itgarden.se. 5 A 45.137.209.211
ns1.itgarden.se. 5 AAAA 2a01:4400:6:0:0:0:0:53
ns2.itgarden.se. 5 AAAA 2a05:d014:ef2:a110:3c11:db9b:6525:ab79
ns3.itgarden.se. 5 AAAA 2a0b:fd82:6000:1:0:0:0:53
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0