Apex domains cannot have CNAME records.
Question and response
Question
dig oss-core.com. NS
Answer
oss-core.com. 2 NS ns1.m2core.com.au.
oss-core.com. 2 NS ns2.m2core.com.au.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0