Apex domains cannot have CNAME records.
Question and response
Question
dig claradns.net. NS
Answer
claradns.net. 5 NS ns1.claradns.net.
claradns.net. 5 NS ns2.claradns.net.
claradns.net. 5 NS ns0.claradns.net.
Authority
The response has no authority records.
Additional
ns0.claradns.net. 5 A 195.245.201.53
ns1.claradns.net. 5 A 185.77.72.50
ns2.claradns.net. 5 A 195.245.201.50
ns0.claradns.net. 5 AAAA 2001:a88:0:fffa:0:0:0:1
ns1.claradns.net. 5 AAAA 2001:67c:1088:0:0:0:0:50
ns2.claradns.net. 5 AAAA 2001:a88:0:fffa:0:0:0:50
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0