Apex domains cannot have CNAME records.
Question and response
Question
dig afd.azureedge.net. NS
Answer
afd.azureedge.net. 5 NS ns2-04.azure-dns.net.
afd.azureedge.net. 5 NS ns1-04.azure-dns.com.
afd.azureedge.net. 5 NS ns4-04.azure-dns.info.
afd.azureedge.net. 5 NS ns3-04.azure-dns.org.
Authority
The response has no authority records.
Additional
ns1-04.azure-dns.com. 5 A 13.107.236.4
ns2-04.azure-dns.net. 5 A 150.171.21.4
ns3-04.azure-dns.org. 5 A 204.14.183.4
ns1-04.azure-dns.com. 5 AAAA 2603:1061:0:700:0:0:0:4
ns2-04.azure-dns.net. 5 AAAA 2620:1ec:8ec:700:0:0:0:4
ns3-04.azure-dns.org. 5 AAAA 2a01:111:4000:700:0:0:0:4
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0