Using “it” for a person is insulting in English.
Using the wrong gender (i.e. addressing a man as “Miss” or “Her”) is vastly more insulting than using “he/she” or “sir/madam”. Be happy English is less gendered than it used to be (at least the 2nd person, “you” is gender-free, and we don’t have to deal with an informal/formal 2nd person which in many languages is a good way to insult someone).