Apex domains cannot have CNAME records.
Question and response
Question
dig sau.net.au. NS
Answer
sau.net.au. 5 NS sonia.ns.cloudflare.com.
sau.net.au. 5 NS jimmy.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0