Apex domains cannot have CNAME records.
Question and response
Question
dig cpinternet.com. NS
Answer
cpinternet.com. 5 NS ns3.ccidns.net.
cpinternet.com. 5 NS ns2.ccidns.net.
cpinternet.com. 5 NS ns1.ccidns.net.
cpinternet.com. 5 NS ns4.ccidns.net.
Authority
The response has no authority records.
Additional
ns1.ccidns.net. 5 A 205.251.193.163
ns2.ccidns.net. 5 A 205.251.194.48
ns3.ccidns.net. 5 A 205.251.199.11
ns4.ccidns.net. 5 A 205.251.197.97
ns1.ccidns.net. 5 AAAA 2600:9000:5301:a300:0:0:0:1
ns2.ccidns.net. 5 AAAA 2600:9000:5302:3000:0:0:0:1
ns3.ccidns.net. 5 AAAA 2600:9000:5307:b00:0:0:0:1
ns4.ccidns.net. 5 AAAA 2600:9000:5305:6100:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0