Apex domains cannot have CNAME records.
Question and response
Question
dig plig.net. NS
Answer
plig.net. 5 NS ns0.plig.net.
plig.net. 5 NS ns1.plig.net.
Authority
The response has no authority records.
Additional
ns0.plig.net. 5 A 178.62.108.205
ns1.plig.net. 5 A 165.227.110.230
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0