Product quantity reset to unlimited when pack added

-- HikaShop version -- : 5.0.3
-- HikaSerial version -- : 4.0.2
-- Joomla version -- : 4.4.3
-- PHP version -- : 8.1.27

Hi,
In the product form, the "quantity" field is set to "unlimited" by default.
If I set it to anything else and I save, it's ok and when I re-open the product form the quantity is there as it was saved.

Now, if I add a pack to the product and hit Save, the "quantity" field is reset to unlimited.

The pack I want to add has a randomgen pack generator.
There is an "unlimited quantity" parameter in the pack: Same behaviour for the product_quantity if set to Yes or No in the pack.

What's wrong?
Thanks