Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-36.com. NS
Answer
awsdns-36.com. 4 NS g-ns-612.awsdns-36.com.
awsdns-36.com. 4 NS g-ns-1188.awsdns-36.com.
awsdns-36.com. 4 NS g-ns-1764.awsdns-36.com.
awsdns-36.com. 4 NS g-ns-37.awsdns-36.com.
Authority
The response has no authority records.
Additional
g-ns-37.awsdns-36.com. 4 A 205.251.192.37
g-ns-612.awsdns-36.com. 4 A 205.251.194.100
g-ns-1188.awsdns-36.com. 4 A 205.251.196.164
g-ns-1764.awsdns-36.com. 4 A 205.251.198.228
g-ns-37.awsdns-36.com. 4 AAAA 2600:9000:5300:2500:0:0:0:1
g-ns-612.awsdns-36.com. 4 AAAA 2600:9000:5302:6400:0:0:0:1
g-ns-1188.awsdns-36.com. 4 AAAA 2600:9000:5304:a400:0:0:0:1
g-ns-1764.awsdns-36.com. 4 AAAA 2600:9000:5306:e400:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0