Ajax Product filter does not work with Non-Latin Character

You could solve this issue with this line of php code in your functions.php of your theme:

add_filter( 'yit_in_array_ignore_case', '__return_true' );

or with this snippet of php code in fuctions.php, too:

if( function_exists('YITH_WCAN') ){
    add_filter('yit_in_array_ignore_case', '__return_true');
    add_filter( 'yith_wcan_term_param_uri', 'yith_wcan_term_param_uri' );

    if( ! function_exists( 'yith_wcan_term_param_uri' ) ){
        function yith_wcan_term_param_uri( $term ){
            $regex = "@^[a-zA-Z0-9%+-_]*$@";
            $is_url_encoded = preg_match( $regex, $term);

            if( $is_url_encoded ){
                $term = urldecode($term);
            }
            return $term;
        }
    }
}