Apex domains cannot have CNAME records.
Question and response
Question
dig stella-net.fr. NS
Answer
stella-net.fr. 5 NS ns500014.as16211.net.
stella-net.fr. 5 NS ns500013.as16211.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0