Apex domains cannot have CNAME records.
Question and response
Question
dig omnibit.it. NS
Answer
omnibit.it. 5 NS dns.widhost.net.
omnibit.it. 5 NS dns2.widhost.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0