Apex domains cannot have CNAME records.
Question and response
Question
dig avernis.net. NS
Answer
avernis.net. 4 NS dns.avernis.eu.
avernis.net. 4 NS dns.avernis.net.
avernis.net. 4 NS dns.avernis.de.
Authority
The response has no authority records.
Additional
dns.avernis.de. 4 A 144.76.27.23
dns.avernis.eu. 4 A 176.9.89.189
dns.avernis.net. 4 A 178.162.221.163
dns.avernis.eu. 4 AAAA 2a01:4f8:151:30a2:0:0:0:189
dns.avernis.net. 4 AAAA 2a00:c98:2200:af0c:10:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0