Apex domains cannot have CNAME records.
Question and response
Question
dig cableazul.net. NS
Answer
cableazul.net. 5 NS NS2.cableazul.net.
cableazul.net. 5 NS NS1.cableazul.net.
Authority
The response has no authority records.
Additional
ns1.cableazul.net. 5 A 5.39.2.8
ns2.cableazul.net. 5 A 5.196.88.111
ns1.cableazul.net. 5 AAAA 2001:41d0:303:ec59:0:0:0:1
ns2.cableazul.net. 5 AAAA 2001:41d0:a:fb6f:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0