Apex domains cannot have CNAME records.
Question and response
Question
dig lyse.net. NS
Answer
lyse.net. 5 NS ns1.altibox.net.
lyse.net. 5 NS ns2.altibox.net.
lyse.net. 5 NS ns3.altibox.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0