Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-42.net. NS
Answer
awsdns-42.net. 5 NS g-ns-1386.awsdns-42.net.
awsdns-42.net. 5 NS g-ns-1962.awsdns-42.net.
awsdns-42.net. 5 NS g-ns-491.awsdns-42.net.
awsdns-42.net. 5 NS g-ns-812.awsdns-42.net.
Authority
The response has no authority records.
Additional
g-ns-491.awsdns-42.net. 5 A 205.251.193.235
g-ns-812.awsdns-42.net. 5 A 205.251.195.44
g-ns-1386.awsdns-42.net. 5 A 205.251.197.106
g-ns-1962.awsdns-42.net. 5 A 205.251.199.170
g-ns-491.awsdns-42.net. 5 AAAA 2600:9000:5301:eb00:0:0:0:1
g-ns-812.awsdns-42.net. 5 AAAA 2600:9000:5303:2c00:0:0:0:1
g-ns-1386.awsdns-42.net. 5 AAAA 2600:9000:5305:6a00:0:0:0:1
g-ns-1962.awsdns-42.net. 5 AAAA 2600:9000:5307:aa00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0