Hi,
Please check that the option "assignable order statuses" is set to "confirmed,shipped".
After that, the order status should be "confirmed" or "shipped" if you want that the serial be assigned to the order.
If your configuration has changed after the order confirmation, you could use the button "refresh association" in the order editing in the backend.
Serials are displayed to the customer only if the serial has a status listed in the option "display serial statuses".
If your pack has the option "consumed", the serial status would not be "used", it would be "assigned" and the default configuration of HikaSerial 1.5.0 is not properly set (it would be fixed in version 1.5.1).
Hope it would help you.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.