Apex domains cannot have CNAME records.
Question and response
Question
dig a3network.se. NS
Answer
a3network.se. 5 NS ns1.allhosting.se.
a3network.se. 5 NS ns2.allhosting.se.
a3network.se. 5 NS ns3.allhosting.se.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0