Apex domains cannot have CNAME records.
Question and response
Question
dig ceconpro.edu.do. NS
Answer
ceconpro.edu.do. 5 NS ns1.c03.tmdcloud.com.
ceconpro.edu.do. 5 NS ns2.c03.tmdcloud.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0