Apex domains cannot have CNAME records.
Question and response
Question
dig duncaexpeditii.ro. NS
Answer
duncaexpeditii.ro. 5 NS venus.o2it.ro.
duncaexpeditii.ro. 5 NS mercur.o2it.ro.
Authority
The response has no authority records.
Additional
mercur.o2it.ro. 5 A 188.214.156.137
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0