Apex domains cannot have CNAME records.
Question and response
Question
dig hpecore.net. NS
Answer
hpecore.net. 2 NS ns3.hpe.com.
hpecore.net. 2 NS ns4.hpe.com.
hpecore.net. 2 NS ns1.hpe.com.
hpecore.net. 2 NS ns7.hpe.com.
hpecore.net. 2 NS ns2.hpe.com.
hpecore.net. 2 NS ns6.hpe.com.
hpecore.net. 2 NS ns5.hpe.com.
hpecore.net. 2 NS ns8.hpe.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0