Item # in Heartland Retail and SKU # in Shopify do not match
Your Item # in Heartland Retail and your SKU # in Shopify must match exactly in order for orders to sync from Shopify to Heartland Retail.
"Draft Orders" are not supported.
If your order is imported manually into Shopify as a "Draft Order," it will not sync down into Heartland Retail.
Missing required fields?
If you have created any required custom fields on either the Customer or the Sales Order pages, it is possible that your sales orders won't sync from Shopify due to these missing required fields. If you mark those fields as unrequired in Heartland Retail under Settings > Custom Fields, your orders should sync successfully.
Orders being auto-fulfilled?
If orders are not syncing because they are already fulfilled. Check under Settings > Checkout > After an order has been paid. It could be that this setting is selected:
Instead you'll want that to be set to: "Do not automatically fulfill any of the order's line items"