Apex domains cannot have CNAME records.
Question and response
Question
dig onecapital.fi. NS
Answer
onecapital.fi. 2 NS ns1.euronic.fi.
onecapital.fi. 2 NS ns3.euronic.fi.
onecapital.fi. 2 NS ns2.euronic.fi.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0