Apex domains cannot have CNAME records.
Question and response
Question
dig smv.mil.do. NS
Answer
smv.mil.do. 2 NS hugh.ns.cloudflare.com.
smv.mil.do. 2 NS aurora.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0