The stock on order amount is not matching what is in Xero - why?

For Xero connections, the Stock on Order in StockTrim is based on your sent purchase orders that haven't been received. 

So ensure that your purchase orders are in Xero correctly and are active (we don't read draft or deleted purchase orders). For PO's that have arrived, ensure that the "Delivery Date" is set on the purchase order so that the quantity no longer contributes to the on order amount in StockTrim. 

We now have an advanced setting that the user can turn on to count "Billed" purchase orders as received. This in place of setting a delivery date on the purchase order.