Apex domains cannot have CNAME records.
Question and response
Question
dig crocierissime.it. NS
Answer
crocierissime.it. 5 NS ns-787.awsdns-34.net.
crocierissime.it. 5 NS ns-1291.awsdns-33.org.
crocierissime.it. 5 NS ns-1584.awsdns-06.co.uk.
crocierissime.it. 5 NS ns-61.awsdns-07.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0