Apex domains cannot have CNAME records.
Question and response
Question
dig acvan.net. NS
Answer
acvan.net. 5 NS ns1.acvan.net.
acvan.net. 5 NS ns2.acvan.net.
acvan.net. 5 NS ns6.acvan.net.
acvan.net. 5 NS ns7.acvan.net.
Authority
The response has no authority records.
Additional
ns1.acvan.net. 5 A 94.103.81.37
ns2.acvan.net. 5 A 62.113.113.34
ns6.acvan.net. 5 A 176.223.129.235
ns1.acvan.net. 5 AAAA 2a0d:8480:1:bc:0:0:0:d
ns2.acvan.net. 5 AAAA 2a0d:8480:0:30e:0:0:0:d
ns6.acvan.net. 5 AAAA 2a02:7b40:b0df:81eb:0:0:0:1
ns7.acvan.net. 5 AAAA 2a05:f480:2400:1ee8:0:0:0:d
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0