Resolving "Compare On Hand" Issues

"Why were On Hand counts subtracted twice?"

It looks like you have synced the counts in the middle of the order fulfillment process (after verified on mobile, before fulfilled on Shopify).

 Here is the correct flow (if fulfilled after QC):

1. Create Shopify Order.
2. Submit order to QC.
3. Verify(scan) the order on mobile.
   3.1. Go to Mobile app > Ship (correct location)
   3.2. Open the created order
   3.3. Go to Products tab
   3.4. Tap Verify
   3.5. Agree to all pop-ups
4. Fulfill Shopify order.
   4.1. Go to Shopify Orders
   4.2. Open the order
   4.3. Click Fulfill item
   4.4. Click Fulfill items
5. Sync Compare On Hand counts.