Looks like Italy is banning the use of overhead bins on flights into, out of and in-country. I haven't read the provision itself yet but the tall and short of it appears to be that if it doesn't fit under the seat, it must be checked. We'll see how long this lasts?
https://www.wantedinrome.com/news/cabin-luggage-ban-on-flights-to-and-from-italy.html
From the Alitalia website:
https://www.alitalia.com/en_en/fly-alitalia/news-and-activities/news/info-flights/flying-safely.html
"From 26 June, following the provision of the Ministry of Health (prot. 21870 of 23 June 2020) and implemented by ENAC, to protect the health of passengers, the use of overhead bins for the storage of hand baggage will no longer be allowed on all flights operated in Italy. Passengers will only be permitted to bring on board small baggage, that can be placed under their seat such as, for example, handbags, backpacks, laptop cases not exceeding 36x45x20 cm. (editing to add: that's roughly 14"x17"x8") We invite passengers to deliver their baggage to the airport at the Check-in / Drop-off counter, to be placed in the hold, free of charge."