Apex domains cannot have CNAME records.
Question and response
Question
dig firstcloudsecurity.net. NS
Answer
firstcloudsecurity.net. 2 NS ns2.firstwave.com.au.
firstcloudsecurity.net. 2 NS ns1.telstra.net.
firstcloudsecurity.net. 2 NS ns1.firstwave.com.au.
firstcloudsecurity.net. 2 NS vm3.is.sydn.nxg.net.au.
Authority
The response has no authority records.
Additional
ns1.firstwave.com.au. 2 A 52.63.104.203
ns2.firstwave.com.au. 2 A 202.137.107.159
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0