Apex domains cannot have CNAME records.
Question and response
Question
dig nic.systems. NS
Answer
nic.systems. 5 NS v2n0.nic.systems.
nic.systems. 5 NS v2n1.nic.systems.
nic.systems. 5 NS v0n0.nic.systems.
nic.systems. 5 NS v0n2.nic.systems.
nic.systems. 5 NS v0n3.nic.systems.
nic.systems. 5 NS v0n1.nic.systems.
Authority
The response has no authority records.
Additional
v0n0.nic.systems. 167692 A 65.22.20.38
v2n1.nic.systems. 167692 A 161.232.11.38
v0n0.nic.systems. 167692 AAAA 2a01:8840:16:0:0:0:0:38
v2n1.nic.systems. 167692 AAAA 2a01:8840:f5:0:0:0:0:38
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0