Apex domains cannot have CNAME records.
Question and response
Question
dig datahjaelp.net. NS
Answer
datahjaelp.net. 5 NS ns6.datahjaelp.net.
datahjaelp.net. 5 NS ns3.datahjaelp.net.
datahjaelp.net. 5 NS ns1.datahjaelp.net.
datahjaelp.net. 5 NS ns2.datahjaelp.net.
datahjaelp.net. 5 NS ns.datahjaelp.net.
Authority
The response has no authority records.
Additional
ns.datahjaelp.net. 5 A 65.108.218.212
ns1.datahjaelp.net. 5 A 65.108.218.212
ns2.datahjaelp.net. 5 A 78.47.118.0
ns3.datahjaelp.net. 5 A 65.21.104.243
ns6.datahjaelp.net. 5 A 116.203.32.238
ns.datahjaelp.net. 5 AAAA 2a01:4f9:c011:bfb3:0:0:0:1
ns1.datahjaelp.net. 5 AAAA 2a01:4f9:c011:bfb3:0:0:0:1
ns2.datahjaelp.net. 5 AAAA 2a01:4f8:c17:86f8:0:0:0:1
ns3.datahjaelp.net. 5 AAAA 2a01:4f9:c010:7c19:0:0:0:1
ns6.datahjaelp.net. 5 AAAA 2a01:4f8:c0c:b7ad:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0