Apex domains cannot have CNAME records.
Question and response
Question
dig secure.nettigritty.com. NS
Answer
secure.nettigritty.com. 5 NS dns1.nettigritty.com.
secure.nettigritty.com. 5 NS dns2.nettigritty.com.
secure.nettigritty.com. 5 NS dns3.nettigritty.com.
Authority
The response has no authority records.
Additional
dns1.nettigritty.com. 5 A 139.59.76.2
dns2.nettigritty.com. 5 A 139.59.76.2
dns3.nettigritty.com. 5 A 172.105.60.6
dns1.nettigritty.com. 5 AAAA 2400:6180:100:d0:0:0:10ab:6001
dns2.nettigritty.com. 5 AAAA 2400:6180:100:d0:0:0:10ab:6001
dns3.nettigritty.com. 5 AAAA 2400:8904:0:0:f03c:92ff:febd:63a2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0