Apex domains cannot have CNAME records.
Question and response
Question
dig d53.nl. NS
Answer
d53.nl. 5 NS ns1.d53.nl.
d53.nl. 5 NS ns2.d53.nl.
Authority
The response has no authority records.
Additional
ns1.d53.nl. 5 A 185.234.20.53
ns2.d53.nl. 5 A 185.234.20.54
ns1.d53.nl. 5 AAAA 2a0c:e640:d53:0:0:0:0:0
ns2.d53.nl. 5 AAAA 2a0c:e640:d54:0:0:0:0:0
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0