Apex domains cannot have CNAME records.
Question and response
Question
dig usgovvirginia.cloudapp.usgovcloudapi.net. NS
Answer
usgovvirginia.cloudapp.usgovcloudapi.net. 4 NS ns4-02.azuregov-dns.us.
usgovvirginia.cloudapp.usgovcloudapi.net. 4 NS ns1-02.azuregov-dns.us.
usgovvirginia.cloudapp.usgovcloudapi.net. 4 NS ns2-02.azuregov-dns.us.
usgovvirginia.cloudapp.usgovcloudapi.net. 4 NS ns3-02.azuregov-dns.us.
Authority
The response has no authority records.
Additional
ns2-02.azuregov-dns.us. 4 A 195.134.226.2
ns4-02.azuregov-dns.us. 4 A 204.13.122.2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0