Apex domains cannot have CNAME records.
Question and response
Question
dig synergywholesale.com. NS
Answer
synergywholesale.com. 5 NS ns1.corp.ventraip.net.au.
synergywholesale.com. 5 NS ns2.corp.ventraip.net.au.
synergywholesale.com. 5 NS ns3.corp.ventraip.net.au.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0