Apex domains cannot have CNAME records.
Question and response
Question
dig hikvision.com. NS
Answer
hikvision.com. 5 NS ns4.dnsv5.com.
hikvision.com. 5 NS ns3.dnsv5.com.
Authority
The response has no authority records.
Additional
ns3.dnsv5.com. 5 A 1.12.0.17
ns3.dnsv5.com. 5 A 1.12.0.18
ns3.dnsv5.com. 5 A 1.12.14.17
ns3.dnsv5.com. 5 A 1.12.14.18
ns3.dnsv5.com. 5 A 35.165.107.227
ns3.dnsv5.com. 5 A 101.227.168.52
ns3.dnsv5.com. 5 A 108.136.87.44
ns3.dnsv5.com. 5 A 163.177.5.52
ns3.dnsv5.com. 5 A 220.196.136.52
ns3.dnsv5.com. 5 AAAA 2402:4e00:1470:2:0:0:0:f
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0