Apex domains cannot have CNAME records.
Question and response
Question
dig corentin-ocean.com. NS
Answer
corentin-ocean.com. 5 NS ns1.corentin-ocean.com.
corentin-ocean.com. 5 NS ns2.corentin-ocean.com.
Authority
The response has no authority records.
Additional
ns1.corentin-ocean.com. 5 A 65.87.27.64
ns2.corentin-ocean.com. 5 A 172.245.168.144
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0