Apex domains cannot have CNAME records.
Question and response
Question
dig uni5.net. NS
Answer
uni5.net. 5 NS dns4.uni5.net.
uni5.net. 5 NS dns1.uni5.net.
uni5.net. 5 NS dns2.uni5.net.
uni5.net. 5 NS dns3.uni5.net.
Authority
The response has no authority records.
Additional
dns1.uni5.net. 5 A 172.64.52.218
dns2.uni5.net. 5 A 162.159.24.210
dns3.uni5.net. 5 A 162.159.25.222
dns4.uni5.net. 5 A 172.64.53.80
dns1.uni5.net. 5 AAAA 2804:10:c011:0:0:0:0:1
dns2.uni5.net. 5 AAAA 2804:10:c022:0:0:0:0:2
dns3.uni5.net. 5 AAAA 2804:10:c033:0:0:0:0:3
dns4.uni5.net. 5 AAAA 2804:10:c044:0:0:0:0:4
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0