Apex domains cannot have CNAME records.
Question and response
Question
dig nwnexus.com. NS
Answer
nwnexus.com. 5 NS ns-2.nuoz.net.
nwnexus.com. 5 NS ns-3.nuoz.net.
nwnexus.com. 5 NS ns-1.nuoz.net.
Authority
The response has no authority records.
Additional
ns-1.nuoz.net. 5 A 216.251.100.50
ns-2.nuoz.net. 5 A 66.228.212.94
ns-3.nuoz.net. 5 A 206.63.32.225
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0