Apex domains cannot have CNAME records.
Question and response
Question
dig gigacomm.net.au. NS
Answer
gigacomm.net.au. 2 NS ns2-02.azure-dns.net.
gigacomm.net.au. 2 NS ns3-02.azure-dns.org.
gigacomm.net.au. 2 NS ns4-02.azure-dns.info.
gigacomm.net.au. 2 NS ns1-02.azure-dns.com.
Authority
The response has no authority records.
Additional
ns1-02.azure-dns.com. 2 A 13.107.236.2
ns2-02.azure-dns.net. 2 A 150.171.21.2
ns3-02.azure-dns.org. 3 A 204.14.183.2
ns1-02.azure-dns.com. 2 AAAA 2603:1061:0:700:0:0:0:2
ns2-02.azure-dns.net. 2 AAAA 2620:1ec:8ec:700:0:0:0:2
ns3-02.azure-dns.org. 3 AAAA 2a01:111:4000:700:0:0:0:2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0