cien.nube-web.com has no CNAME records.
Question and response
Question
dig cien.nube-web.com. NS
Answer
The response has no answer records.
Authority
nube-web.com. 1974 SOA ns1.sectigoweb.com. admin.sectigo.com. 1714139966 86400 7200 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0