Apex domains cannot have CNAME records.
Question and response
Question
dig eserver.net. NS
Answer
eserver.net. 5 NS ns2.eserver.net.
eserver.net. 5 NS ns1.eserver.net.
eserver.net. 5 NS ns4.eserver.net.
eserver.net. 5 NS ns3.eserver.net.
Authority
The response has no authority records.
Additional
ns1.eserver.net. 5 A 185.48.248.22
ns2.eserver.net. 5 A 185.48.249.22
ns3.eserver.net. 5 A 185.48.248.222
ns4.eserver.net. 5 A 91.219.236.163
ns1.eserver.net. 5 AAAA 2a04:b540:0:0:0:0:0:11
ns2.eserver.net. 5 AAAA 2a04:b540:1:2:0:0:0:11
ns3.eserver.net. 5 AAAA 2a04:b540:1:2:0:0:0:3
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0