Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-12.net. NS
Answer
awsdns-12.net. 5 NS g-ns-1932.awsdns-12.net.
awsdns-12.net. 5 NS g-ns-782.awsdns-12.net.
awsdns-12.net. 5 NS g-ns-461.awsdns-12.net.
awsdns-12.net. 5 NS g-ns-1356.awsdns-12.net.
Authority
The response has no authority records.
Additional
g-ns-461.awsdns-12.net. 5 A 205.251.193.205
g-ns-782.awsdns-12.net. 5 A 205.251.195.14
g-ns-1356.awsdns-12.net. 5 A 205.251.197.76
g-ns-1932.awsdns-12.net. 5 A 205.251.199.140
g-ns-461.awsdns-12.net. 5 AAAA 2600:9000:5301:cd00:0:0:0:1
g-ns-782.awsdns-12.net. 5 AAAA 2600:9000:5303:e00:0:0:0:1
g-ns-1356.awsdns-12.net. 5 AAAA 2600:9000:5305:4c00:0:0:0:1
g-ns-1932.awsdns-12.net. 5 AAAA 2600:9000:5307:8c00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0