Apex domains cannot have CNAME records.
Question and response
Question
dig i3d.nl. NS
Answer
i3d.nl. 5 NS ns3.i3d.network.
i3d.nl. 5 NS ns1.i3d.nl.
i3d.nl. 5 NS ns2.i3d.net.
Authority
The response has no authority records.
Additional
ns1.i3d.nl. 5 A 213.163.76.133
ns2.i3d.net. 5 A 162.244.52.53
ns3.i3d.network. 5 A 103.194.166.85
ns1.i3d.nl. 5 AAAA 2a00:1630:1:100:0:0:0:53
ns2.i3d.net. 5 AAAA 2a04:c604:501:0:0:0:0:53
ns3.i3d.network. 5 AAAA 2a00:1633:48:0:0:0:0:53
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0