Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-25.net. NS
Answer
awsdns-25.net. 5 NS g-ns-474.awsdns-25.net.
awsdns-25.net. 5 NS g-ns-1369.awsdns-25.net.
awsdns-25.net. 5 NS g-ns-795.awsdns-25.net.
awsdns-25.net. 5 NS g-ns-1945.awsdns-25.net.
Authority
The response has no authority records.
Additional
g-ns-474.awsdns-25.net. 5 A 205.251.193.218
g-ns-795.awsdns-25.net. 5 A 205.251.195.27
g-ns-1369.awsdns-25.net. 5 A 205.251.197.89
g-ns-1945.awsdns-25.net. 5 A 205.251.199.153
g-ns-474.awsdns-25.net. 5 AAAA 2600:9000:5301:da00:0:0:0:1
g-ns-795.awsdns-25.net. 5 AAAA 2600:9000:5303:1b00:0:0:0:1
g-ns-1369.awsdns-25.net. 5 AAAA 2600:9000:5305:5900:0:0:0:1
g-ns-1945.awsdns-25.net. 5 AAAA 2600:9000:5307:9900:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0