Hi,
We just made few fixes about that, please try to edit the file "administrator/components/com_hikashop/classes/address.php" and replace:
$currentTask = 'shipping_address';
if( (empty($task) || $task == $currentTask) && !empty($data[$currentTask])) {
By:
$same_address = JRequest::getString('same_address');
$currentTask = 'shipping_address';
if( (empty($task) || $task == $currentTask) && !empty($data[$currentTask]) && $same_address != 'yes') {
If this code solve your issue, so it was coming from a check done on the shipping address even if the "use same address" checkbox is checked.