Apex domains cannot have CNAME records.
Question and response
Question
dig acemsa4.com. NS
Answer
acemsa4.com. 5 NS ns-249.awsdns-31.com.
acemsa4.com. 5 NS ns-676.awsdns-20.net.
acemsa4.com. 5 NS ns-1307.awsdns-35.org.
acemsa4.com. 5 NS ns-1645.awsdns-13.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0