ns3.solver.net.ua has no NS records.
NS records for this zone are defined at net.ua.
NS records for this zone are defined at net.ua.
Question and response
Question
dig ns3.solver.net.ua. NS
Answer
The response has no answer records.
Authority
solver.net.ua. 968 SOA ns.solver.net.ua. root.margadon.kot.poltava.ua. 2026010601 86400 3600 3600000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0