Apex domains cannot have CNAME records.
Question and response
Question
dig infolix.fr. NS
Answer
infolix.fr. 4 NS ns1.infolix.fr.
infolix.fr. 4 NS ns2.infolix.fr.
Authority
The response has no authority records.
Additional
ns1.infolix.fr. 4 A 87.106.215.208
ns2.infolix.fr. 4 A 54.36.46.225
ns1.infolix.fr. 4 AAAA 2a02:2479:7c:9b00:0:0:0:1
ns2.infolix.fr. 4 AAAA 2001:41d0:203:4028:0:0:0:351
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0