WordPress GDPR Comments w/ Polylang via Child Theme

functions.php

<?php

function register_pll_strings() {

	if( !function_exists( 'pll_register_string' ) ) return; // go away if polylang not active

	pll_register_string('Policy Accept', 'I read your', 'CommentForm');
	pll_register_string('Privacy Policy', 'Privacy Policy', 'CommentForm');
	pll_register_string('Policy Page', 'privacy', 'CommentForm');
	pll_register_string('Error', 'ERROR', 'CommentForm');
	pll_register_string('Error Text', 'You must agree to our Privacy Policy.', 'CommentForm');

}
add_action( 'init', 'register_pll_strings' );

function custom_comment_consent_fields( $fields ) {

	if( !function_exists( 'pll__' ) ) return; // go away if polylang not active

	$site_url = get_site_url();
	$locale_simple = substr( get_locale(), 0, 2 );
	$locale_url = $site_url .'/'. $locale_simple .'/';

	$privacy_policy_consent_label = pll__( 'I read your' ) .' <a href="'. $locale_url . pll__( 'privacy' ) .'">'. pll__( 'Privacy Policy' ) .'</a>.';

	$fields['policy-consent'] =
		'<p class="comment-form-policy-consent">
			<input id="wp-comment-policy-consent" name="wp-comment-policy-consent" value="yes" type="checkbox"'. ( isset( $_COOKIE['comment_author_privacy_' . COOKIEHASH] )  ? ' checked="checked"' : '' ) .' aria-required="true">
			<label for="wp-comment-policy-consent">'. $privacy_policy_consent_label .'</label>
			<span class="comment-form-policy__required required">*</span>
		</p>';

    return $fields;
}

add_filter('comment_form_default_fields', 'custom_comment_consent_fields');

function verify_policy_consented( $commentdata ) {

	if( !function_exists( 'pll__' ) ) return; // go away if polylang not active

	if ( !isset( $_POST['wp-comment-policy-consent'] ) && !is_user_logged_in() ) {

		$privacy_policy_consent_error = '<strong>'. pll__( 'ERROR' ) .':</strong>&nbsp;'. pll__( 'You must accept our Privacy Policy.' );
		wp_die( $privacy_policy_consent_error . '<p><a href="javascript:history.back()">' . __('&laquo; Back') . '</a></p>');

	} else {

		$hashed_cookie = 'comment_author_privacy_' . COOKIEHASH;
		if ( isset( $_POST['wp-comment-cookies-consent'] ) ) {

			setcookie( $hashed_cookie, 1, time() + 3600 * 24 * 100, COOKIEPATH, COOKIE_DOMAIN, false );

		} else {

			setcookie( $hashed_cookie, '', time() - 3600, COOKIEPATH, COOKIE_DOMAIN );

		}
	}

	return $commentdata;

}
add_filter('preprocess_comment', 'verify_policy_consented');