Apex domains cannot have CNAME records.
Question and response
Question
dig _d.mim.ec. NS
Answer
_d.mim.ec. 4 NS ns-2008.awsdns-59.co.uk.
_d.mim.ec. 4 NS ns-1522.awsdns-62.org.
_d.mim.ec. 4 NS ns-109.awsdns-13.com.
_d.mim.ec. 4 NS ns-930.awsdns-52.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0