proxy.man.lodz.pl has no CNAME records.
Question and response
Question
dig proxy.man.lodz.pl. NS
Answer
The response has no answer records.
Authority
man.lodz.pl. 600 SOA dns2.man.lodz.pl. root.man.lodz.pl. 2026022602 10800 1800 3600000 8640
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0