Apex domains cannot have CNAME records.
Question and response
Question
dig dulceriodelbueno.com. NS
Answer
dulceriodelbueno.com. 5 NS ns-1919.awsdns-47.co.uk.
dulceriodelbueno.com. 5 NS ns-1688.awsdns-19.co.uk.
dulceriodelbueno.com. 5 NS ns-1341.awsdns-39.org.
dulceriodelbueno.com. 5 NS ns-1604.awsdns-08.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0