Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-19.net. NS
Answer
awsdns-19.net. 5 NS g-ns-1363.awsdns-19.net.
awsdns-19.net. 5 NS g-ns-468.awsdns-19.net.
awsdns-19.net. 5 NS g-ns-789.awsdns-19.net.
awsdns-19.net. 5 NS g-ns-1939.awsdns-19.net.
Authority
The response has no authority records.
Additional
g-ns-468.awsdns-19.net. 5 A 205.251.193.212
g-ns-789.awsdns-19.net. 5 A 205.251.195.21
g-ns-1363.awsdns-19.net. 5 A 205.251.197.83
g-ns-1939.awsdns-19.net. 5 A 205.251.199.147
g-ns-468.awsdns-19.net. 5 AAAA 2600:9000:5301:d400:0:0:0:1
g-ns-789.awsdns-19.net. 5 AAAA 2600:9000:5303:1500:0:0:0:1
g-ns-1363.awsdns-19.net. 5 AAAA 2600:9000:5305:5300:0:0:0:1
g-ns-1939.awsdns-19.net. 5 AAAA 2600:9000:5307:9300:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0