Apex domains cannot have CNAME records.
Question and response
Question
dig ek-hosting.nl. NS
Answer
ek-hosting.nl. 4 NS ruth.ns.cloudflare.com.
ek-hosting.nl. 4 NS sri.ns.cloudflare.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0