Hi,
I think you have the option "link product quantity" activated.
www.hikashop.com/support/documentation/1...ink_product_quantity
If the pack does not have a plugin generator, HikaSerial would count the "serials" stock and change the product quantity depending his link.
But that's not explain clearly (it is implicit), when the pack have a plugin generator, we consider that the product quantity is unlimited.
And you are right, the series generator have a limitation but when we create this option of link product quantity, we didn't though that it will be possible to have a no-unlimited generator.
I created an entry in my TODO list in order to fix it, which I consider as a bug (or a missing feature).
Regards,