ACF4 get_field() issue when $format_value = false (repeater field with a google_map field inside)

acf4.php

<?php

// repeater field = field_56203ac21790a
get_field( 'field_56203ac21790a', $post_id, $format_value = false );

// result
int(2)

acf5.php

<?php

get_field( 'field_56203ac21790a', $post_id, $format_value = false );

// result
array(2) {
  [0]=>
  array(1) {
    ["field_56203acd1790b"]=>
    array(3) {
      ["address"]=>
      string(29) "Richmond, Victoria, Australia"
      ["lat"]=>
      string(10) "-37.818635"
      ["lng"]=>
      string(18) "145.00147040000002"
    }
  }
  [1]=>
  array(1) {
    ["field_56203acd1790b"]=>
    array(3) {
      ["address"]=>
      string(42) "Inner Harbor, Baltimore, MD, United States"
      ["lat"]=>
      string(10) "39.2858482"
      ["lng"]=>
      string(11) "-76.6131105"
    }
  }
}