Apex domains cannot have CNAME records.
Question and response
Question
dig netset.se. NS
Answer
netset.se. 5 NS ns2.netset.se.
netset.se. 5 NS ns4.netset.se.
netset.se. 5 NS ns.netset.se.
netset.se. 5 NS ns1.netset.se.
Authority
The response has no authority records.
Additional
ns.netset.se. 5 A 194.16.65.242
ns1.netset.se. 5 A 157.245.64.199
ns2.netset.se. 5 A 85.118.201.219
ns4.netset.se. 5 A 185.112.138.6
ns1.netset.se. 5 AAAA 2a03:b0c0:2:f0:0:0:e259:5001
ns2.netset.se. 5 AAAA 2a06:6187:2:101:0:0:0:3
ns4.netset.se. 5 AAAA 2a06:6187:4002:101:0:0:0:2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0