Apex domains cannot have CNAME records.
Question and response
Question
dig com.ua. NS
Answer
com.ua. 5 NS nn.ns.ua.
com.ua. 5 NS rcz.ns.ua.
com.ua. 5 NS ho1.com.ns.ua.
com.ua. 5 NS cz.ns.ua.
com.ua. 5 NS cfdf.com.ns.ua.
Authority
The response has no authority records.
Additional
rcz.ns.ua. 171202 A 193.46.128.10
rcz.ns.ua. 171202 AAAA 2a02:850:ffe0:0:0:0:0:10
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0