Apex domains cannot have CNAME records.
Question and response
Question
dig grand-sebaste.com. NS
Answer
grand-sebaste.com. 4 NS ns1.grand-sebaste.com.
grand-sebaste.com. 4 NS ns2.grand-sebaste.com.
Authority
The response has no authority records.
Additional
ns1.grand-sebaste.com. 4 A 170.130.202.146
ns2.grand-sebaste.com. 4 A 23.231.64.60
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0