Please note,
- Shopify does not immediately fulfill gift card orders automatically. It is by checkout settings.
- Even if fulfilled, Acumatica will import these orders.
- Acumatica will not import only the Archived orders.
So with that, what I would suggest you is either you should make Gift Cards not be fulfilled automatically or make the order not to be Archived as soon as it is fulfilled. I would go with the former.
Please see the below screenshot for more clarity. It is excerpt from Shopify Checkout settings.