Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-27.net. NS
Answer
awsdns-27.net. 5 NS g-ns-1371.awsdns-27.net.
awsdns-27.net. 5 NS g-ns-797.awsdns-27.net.
awsdns-27.net. 5 NS g-ns-476.awsdns-27.net.
awsdns-27.net. 5 NS g-ns-1947.awsdns-27.net.
Authority
The response has no authority records.
Additional
g-ns-476.awsdns-27.net. 5 A 205.251.193.220
g-ns-797.awsdns-27.net. 5 A 205.251.195.29
g-ns-1371.awsdns-27.net. 5 A 205.251.197.91
g-ns-1947.awsdns-27.net. 5 A 205.251.199.155
g-ns-476.awsdns-27.net. 5 AAAA 2600:9000:5301:dc00:0:0:0:1
g-ns-797.awsdns-27.net. 5 AAAA 2600:9000:5303:1d00:0:0:0:1
g-ns-1371.awsdns-27.net. 5 AAAA 2600:9000:5305:5b00:0:0:0:1
g-ns-1947.awsdns-27.net. 5 AAAA 2600:9000:5307:9b00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0