Apex domains cannot have CNAME records.
Question and response
Question
dig ufinet.com.gt. NS
Answer
ufinet.com.gt. 4 NS ns2.ufinetlatam.net.
ufinet.com.gt. 4 NS ns1.ufinetlatam.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0