Apex domains cannot have CNAME records.
Question and response
Question
dig qcapwtestinternal.com.au. NS
Answer
qcapwtestinternal.com.au. 4 NS dns1.cscdns.net.
qcapwtestinternal.com.au. 4 NS dns2.cscdns.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0