Apex domains cannot have CNAME records.
Question and response
Question
dig xetdns.com. NS
Answer
xetdns.com. 5 NS ns1.atw.hu.
xetdns.com. 5 NS ns5.atw.hu.
Authority
The response has no authority records.
Additional
ns1.atw.hu. 3 A 88.151.96.11
ns5.atw.hu. 3 A 94.125.176.1
ns1.atw.hu. 3 AAAA 2a01:270:0:2:0:0:0:11
ns5.atw.hu. 3 AAAA 2a01:270:0:2:0:0:0:16
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0