Apex domains cannot have CNAME records.
Question and response
Question
dig frontiersoftware.com.au. NS
Answer
frontiersoftware.com.au. 3 NS ns2.intellicentre.net.au.
frontiersoftware.com.au. 3 NS ns3.intellicentre.net.au.
frontiersoftware.com.au. 3 NS ns1.intellicentre.net.au.
Authority
The response has no authority records.
Additional
ns1.intellicentre.net.au. 4 A 203.110.136.160
ns2.intellicentre.net.au. 4 A 124.47.130.30
ns3.intellicentre.net.au. 3 A 124.47.142.2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0