Apex domains cannot have CNAME records.
Question and response
Question
dig mhznetwork.com. NS
Answer
mhznetwork.com. 5 NS ns-1542.awsdns-00.co.uk.
mhznetwork.com. 5 NS ns-1450.awsdns-53.org.
mhznetwork.com. 5 NS ns-455.awsdns-56.com.
mhznetwork.com. 5 NS ns-511.awsdns-63.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0