Apex domains cannot have CNAME records.
Question and response
Question
dig dnsres.net. NS
Answer
dnsres.net. 5 NS anycast1.dnsres.net.
dnsres.net. 5 NS anycast2.dnsres.net.
Authority
The response has no authority records.
Additional
anycast1.dnsres.net. 5 A 193.227.117.227
anycast2.dnsres.net. 5 A 194.50.187.227
anycast1.dnsres.net. 5 AAAA 2a04:2b00:14cc:0:0:0:0:227
anycast2.dnsres.net. 5 AAAA 2a04:2b00:14dd:0:0:0:0:227
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0