Apex domains cannot have CNAME records.
Question and response
Question
dig srvxny44.xponzy.com. NS
Answer
srvxny44.xponzy.com. 5 NS ns2.xponzy.com.
srvxny44.xponzy.com. 5 NS ns1.xponzy.com.
Authority
The response has no authority records.
Additional
ns1.xponzy.com. 5 A 70.23.213.188
ns2.xponzy.com. 5 A 70.23.213.187
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0