I think you're right. Italian is not an ethnicity. Italy hasn't been a unified political entity for very long. There are Italians from all sorts of different ethnicities and races. Would it be okay for a Black person to play this role if they were Italian? If not, why is it okay for non-Italian white actors to play other roles?
Is a Corsican person Italian? Is an Italian-American? Is Mario Balotelli (for example)? Why does any of this matter?
Oh brother…
I was not born in Italy, but I am of Italian descent btw. Not sure why that matters, but it probably does to you :-/
Also, I guess you mean only true northern Italians can play the character lol why don’t you phrase it like that as well. See how absurd it sounds?