Apex domains cannot have CNAME records.
Question and response
Question
dig plateautel.net. NS
Answer
plateautel.net. 5 NS ns2.plateautel.net.
plateautel.net. 5 NS ns1.plateautel.net.
Authority
The response has no authority records.
Additional
ns1.plateautel.net. 5 A 68.66.93.182
ns2.plateautel.net. 5 A 74.50.129.214
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0