Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-50.net. NS
Answer
awsdns-50.net. 5 NS g-ns-820.awsdns-50.net.
awsdns-50.net. 5 NS g-ns-499.awsdns-50.net.
awsdns-50.net. 5 NS g-ns-1970.awsdns-50.net.
awsdns-50.net. 5 NS g-ns-1394.awsdns-50.net.
Authority
The response has no authority records.
Additional
g-ns-499.awsdns-50.net. 5 A 205.251.193.243
g-ns-820.awsdns-50.net. 5 A 205.251.195.52
g-ns-1394.awsdns-50.net. 5 A 205.251.197.114
g-ns-1970.awsdns-50.net. 5 A 205.251.199.178
g-ns-499.awsdns-50.net. 5 AAAA 2600:9000:5301:f300:0:0:0:1
g-ns-820.awsdns-50.net. 5 AAAA 2600:9000:5303:3400:0:0:0:1
g-ns-1394.awsdns-50.net. 5 AAAA 2600:9000:5305:7200:0:0:0:1
g-ns-1970.awsdns-50.net. 5 AAAA 2600:9000:5307:b200:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0