Apex domains cannot have CNAME records.
Question and response
Question
dig access4.com.au. NS
Answer
access4.com.au. 5 NS ns-10.awsdns-01.com.
access4.com.au. 5 NS ns-1609.awsdns-09.co.uk.
access4.com.au. 5 NS ns-1128.awsdns-13.org.
access4.com.au. 5 NS ns-550.awsdns-04.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0