Apex domains cannot have CNAME records.
Question and response
Question
dig sigeben.net.do. NS
Answer
sigeben.net.do. 5 NS ns-347.awsdns-43.com.
sigeben.net.do. 5 NS ns-561.awsdns-06.net.
sigeben.net.do. 5 NS ns-1144.awsdns-15.org.
sigeben.net.do. 5 NS ns-2007.awsdns-58.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0