Apex domains cannot have CNAME records.
Question and response
Question
dig srv.gitoyen.net. NS
Answer
srv.gitoyen.net. 2 NS ns2.gitoyen.net.
srv.gitoyen.net. 2 NS ns1.gitoyen.net.
Authority
The response has no authority records.
Additional
ns1.gitoyen.net. 2 A 80.67.163.156
ns2.gitoyen.net. 2 A 91.224.149.46
ns1.gitoyen.net. 2 AAAA 2001:910:0:40:0:0:0:156
ns2.gitoyen.net. 2 AAAA 2a03:7220:8081:2e00:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0