Apex domains cannot have CNAME records.
Question and response
Question
dig medimmobiliare.com. NS
Answer
medimmobiliare.com. 5 NS ns-1155.awsdns-16.org.
medimmobiliare.com. 5 NS ns-1811.awsdns-34.co.uk.
medimmobiliare.com. 5 NS ns-588.awsdns-09.net.
medimmobiliare.com. 5 NS ns-1324.awsdns-37.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0