Apex domains cannot have CNAME records.
Question and response
Question
dig blix.eu. NS
Answer
blix.eu. 5 NS ns2.blix.eu.
blix.eu. 5 NS ns1.blix.com.
Authority
The response has no authority records.
Additional
ns1.blix.com. 5 A 91.205.184.10
ns2.blix.eu. 5 A 91.205.187.202
ns1.blix.com. 5 AAAA 2a02:20c8:10:0:0:0:0:2
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0