Apex domains cannot have CNAME records.
Question and response
Question
dig fundaments.cloud. NS
Answer
fundaments.cloud. 5 NS ns1.oxilion.nl.
fundaments.cloud. 5 NS ns3.oxilion.net.
fundaments.cloud. 5 NS ns2.oxilion.nl.
Authority
The response has no authority records.
Additional
ns1.oxilion.nl. 3 A 93.186.179.180
ns2.oxilion.nl. 3 A 93.186.184.50
ns3.oxilion.net. 3 A 213.206.97.203
ns1.oxilion.nl. 3 AAAA 2a00:d10:0:0:0:0:53:1
ns2.oxilion.nl. 3 AAAA 2a00:d10:3:0:0:0:53:2
ns3.oxilion.net. 3 AAAA 2001:898:2000:1000:0:0:0:5
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0