Why is AO average cost different from QB?

The average cost in All Orders is pulled directly from QB. Notice in the Inventory Item screen, of AO, that the average cost is not a field that you can update. That is because AO does not calculate the average cost, instead it pulls the average cost from QB. Therefore, send any transactions that need to be sent to QB so that it can recalculate the average cost. Next, do a sync so that AO's average cost will be updated. In AO, the Valuation report is FIFO cost, and the Valuation in QB is Weighted Average cost.