“is a required field” not translated.

Hi, I have this problem from a long time and more than a theme.
I now have this site build with storefront and the string “is a required field” given in error messages in checkout is not trnslated.
Opening woocommerce-it_IT.po and woocommerce-it_IT.mo, the string

%s is a required field
is correctly translated with
è un campo obbligatorio
in italian.

The woocommerce file class-wc-checkout.php contains the string that has to be translated:

				if ( $validate_fieldset && $required && '' === $data[ $key ] ) {
					/* translators: %s: field name */
					$errors->add( 'required-field', apply_filters( 'woocommerce_checkout_required_field_notice', sprintf( __( '<strong>%s is a required field.</strong>', 'woocommerce' ), '<strong>' . esc_html( $field_label ) . '</strong>' ), $field_label ), array( 'id' => $key ) );
				}

but…nothing. traslation doesn’t show on frontend.

I had this problem with other strings starting with “%” in woocommerce and I found some solutions to avoid it, overriding templates etc. But with this file in woocommerce\includes it can’t be done.

Any suggestion?

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