Apex domains cannot have CNAME records.
Question and response
Question
dig furanet.com. NS
Answer
furanet.com. 5 NS dns3.hispalisdns.com.
furanet.com. 5 NS dns1.hispalisdns.com.
furanet.com. 5 NS dns2.hispalisdns.com.
Authority
The response has no authority records.
Additional
dns1.hispalisdns.com. 5 A 77.81.116.119
dns2.hispalisdns.com. 5 A 5.145.169.10
dns3.hispalisdns.com. 5 A 144.217.66.189
dns1.hispalisdns.com. 5 AAAA 2a00:1d70:1:0:0:0:116:119
dns2.hispalisdns.com. 5 AAAA 2a00:1d70:c01c:0:0:0:169:10
dns3.hispalisdns.com. 5 AAAA 2607:5300:60:cabd:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0