Apex domains cannot have CNAME records.
Question and response
Question
dig maxnet.ua. NS
Answer
maxnet.ua. 5 NS ns.maxnet.ua.
maxnet.ua. 5 NS ns8.maxnet.ua.
maxnet.ua. 5 NS ns5.maxnet.ua.
maxnet.ua. 5 NS nss.maxnet.ua.
maxnet.ua. 5 NS ns9.maxnet.ua.
Authority
The response has no authority records.
Additional
ns.maxnet.ua. 5 A 79.171.120.1
ns5.maxnet.ua. 5 A 178.165.81.4
ns8.maxnet.ua. 5 A 31.202.15.2
ns9.maxnet.ua. 5 A 217.196.160.2
nss.maxnet.ua. 5 A 79.171.120.3
ns.maxnet.ua. 5 AAAA 2a00:1210:0:9:0:0:1:1
ns5.maxnet.ua. 5 AAAA 2a00:1210:0:2:0:0:0:2
ns8.maxnet.ua. 5 AAAA 2a00:1210:fffe:0:0:0:0:2
ns9.maxnet.ua. 5 AAAA 2a00:1210:fffd:fff0:0:0:0:2
nss.maxnet.ua. 5 AAAA 2a00:1210:0:9:0:0:2:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0