ns1.rsweb.com.do has no CNAME records.
Question and response
Question
dig ns1.rsweb.com.do. NS
Answer
The response has no answer records.
Authority
rsweb.com.do. 9734 SOA ns1.rsweb.com.do. servers.privatednsorg.com. 2026030200 86400 7200 1600000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0