Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-38.com. NS
Answer
awsdns-38.com. 5 NS g-ns-39.awsdns-38.com.
awsdns-38.com. 5 NS g-ns-614.awsdns-38.com.
awsdns-38.com. 5 NS g-ns-1190.awsdns-38.com.
awsdns-38.com. 5 NS g-ns-1766.awsdns-38.com.
Authority
The response has no authority records.
Additional
g-ns-39.awsdns-38.com. 5 A 205.251.192.39
g-ns-614.awsdns-38.com. 5 A 205.251.194.102
g-ns-1190.awsdns-38.com. 5 A 205.251.196.166
g-ns-1766.awsdns-38.com. 5 A 205.251.198.230
g-ns-39.awsdns-38.com. 5 AAAA 2600:9000:5300:2700:0:0:0:1
g-ns-614.awsdns-38.com. 5 AAAA 2600:9000:5302:6600:0:0:0:1
g-ns-1190.awsdns-38.com. 5 AAAA 2600:9000:5304:a600:0:0:0:1
g-ns-1766.awsdns-38.com. 5 AAAA 2600:9000:5306:e600:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0