Apex domains cannot have CNAME records.
Question and response
Question
dig mtgsy.net. NS
Answer
mtgsy.net. 3 NS ns4.g12.cfdns.co.uk.
mtgsy.net. 3 NS ns2.g12.cfdns.biz.
mtgsy.net. 3 NS ns1.g12.cfdns.net.
mtgsy.net. 3 NS ns3.g12.cfdns.info.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0