Apex domains cannot have CNAME records.
Question and response
Question
dig hv2.octosquid.com. NS
Answer
hv2.octosquid.com. 5 NS dns2.host-vision.com.
hv2.octosquid.com. 5 NS dns1.host-vision.com.
Authority
The response has no authority records.
Additional
dns1.host-vision.com. 5 A 46.4.107.20
dns2.host-vision.com. 5 A 176.126.200.40
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0