Apex domains cannot have CNAME records.
Question and response
Question
dig bcs.ee. NS
Answer
bcs.ee. 5 NS ns.elkdata.ee.
bcs.ee. 5 NS ns3.elkdata.net.
bcs.ee. 5 NS ns2.elkdata.ee.
Authority
The response has no authority records.
Additional
ns.elkdata.ee. 5 A 194.106.101.162
ns2.elkdata.ee. 5 A 194.106.101.163
ns3.elkdata.net. 5 A 195.222.17.113
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0