Apex domains cannot have CNAME records.
Question and response
Question
dig box3.pl. NS
Answer
box3.pl. 5 NS dns3.box3.pl.
box3.pl. 5 NS dns1.box3.pl.
box3.pl. 5 NS dns2.box3.pl.
Authority
The response has no authority records.
Additional
dns1.box3.pl. 5 A 176.114.232.11
dns1.box3.pl. 5 A 176.114.232.13
dns2.box3.pl. 5 A 176.113.232.13
dns2.box3.pl. 5 A 176.114.232.11
dns2.box3.pl. 5 A 176.114.232.20
dns2.box3.pl. 5 A 176.114.232.29
dns3.box3.pl. 5 A 176.114.232.3
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0