Apex domains cannot have CNAME records.
Question and response
Question
dig clouditalia.com. NS
Answer
clouditalia.com. 5 NS mnt2.eutelia.it.
clouditalia.com. 5 NS mnt1.eutelia.it.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0