Apex domains cannot have CNAME records.
Question and response
Question
dig cityhost.com.ua. NS
Answer
cityhost.com.ua. 5 NS ns2.controlpanel.host.
cityhost.com.ua. 5 NS ns3.controlpanel.host.
cityhost.com.ua. 5 NS ns1.controlpanel.host.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0