Apex domains cannot have CNAME records.
Question and response
Question
dig tamico.com. NS
Answer
tamico.com. 5 NS ns1.tamico.fi.
tamico.com. 5 NS ns3.tamico.fi.
tamico.com. 5 NS ns2.tamico.com.
Authority
The response has no authority records.
Additional
ns1.tamico.fi. 5 A 88.148.137.100
ns2.tamico.com. 5 A 178.62.167.229
ns3.tamico.fi. 5 A 178.62.167.229
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0