Apex domains cannot have CNAME records.
Question and response
Question
dig acr-sud.com. NS
Answer
acr-sud.com. 2 NS ns-145.awsdns-18.com.
acr-sud.com. 2 NS ns-1184.awsdns-20.org.
acr-sud.com. 2 NS ns-351.awsdns-43.com.
acr-sud.com. 2 NS ns-1309.awsdns-35.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0