Apex domains cannot have CNAME records.
Question and response
Question
dig acens.com. NS
Answer
acens.com. 5 NS ns2.acens.net.
acens.com. 5 NS ns1.acens.net.
Authority
The response has no authority records.
Additional
ns1.acens.net. 5 A 217.116.0.176
ns2.acens.net. 5 A 217.116.0.177
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0