Apex domains cannot have CNAME records.
Question and response
Question
dig mx71.net. NS
Answer
mx71.net. 5 NS ns1.ns71.net.
mx71.net. 5 NS ns3.ns71.net.
mx71.net. 5 NS ns2.ns71.net.
Authority
The response has no authority records.
Additional
. 0 OPT [{Extended_DNS_Error: SIGNATURE_EXPIRED: mx71.net/DNSKEY}] ; payload 1232, xrcode 0, version 0, flags 0