Apex domains cannot have CNAME records.
Question and response
Question
dig tigocloud.net. NS
Answer
tigocloud.net. 5 NS ns-620.awsdns-13.net.
tigocloud.net. 5 NS ns-149.awsdns-18.com.
tigocloud.net. 5 NS ns-2010.awsdns-59.co.uk.
tigocloud.net. 5 NS ns-1325.awsdns-37.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0