Apex domains cannot have CNAME records.
Question and response
Question
dig cloudsrvr.nl. NS
Answer
cloudsrvr.nl. 4 NS nsn1.mijndomein.nl.
cloudsrvr.nl. 4 NS nsn2.mijndomein.nl.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0