Apex domains cannot have CNAME records.
Question and response
Question
dig racv.com.au. NS
Answer
racv.com.au. 4 NS ns-1734.awsdns-24.co.uk.
racv.com.au. 4 NS ns-1447.awsdns-52.org.
racv.com.au. 4 NS ns-500.awsdns-62.com.
racv.com.au. 4 NS ns-850.awsdns-42.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0