Apex domains cannot have CNAME records.
Question and response
Question
dig orbgny.alticeusa.net. NS
Answer
orbgny.alticeusa.net. 5 NS authns1.cv.net.
orbgny.alticeusa.net. 5 NS authns1.cvnet.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0