Apex domains cannot have CNAME records.
Question and response
Question
dig oxsus-vadesecure.net. NS
Answer
oxsus-vadesecure.net. 4 NS ns-1132.awsdns-13.org.
oxsus-vadesecure.net. 4 NS ns-1895.awsdns-44.co.uk.
oxsus-vadesecure.net. 4 NS ns-205.awsdns-25.com.
oxsus-vadesecure.net. 4 NS ns-603.awsdns-11.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0