I am also experiencing this issue. I have an item that is kept per unit in stock. But is purchased as boxes of 50 units. I have placed the item’s purchased unit of measure table. Indicated the Unit as 1 conversion factor and Box as 50 conversion factor. This in theory is supposed to convert 1 Box as 50 Units.
When I create a purchase order and add the item, it defaults to loading the default item’s UOM which is Unit. So it comes out as quantity 1 x price list rate. I click the arrow in the right side of the item row to edit the item details. Under “Quantity and Rate” it indicates Quanity 1, Stock UOM as Unit, UOM as Unit, then UOM Conversion Factor 1. I then proceed to change the UOM as Box. UOM Conversion Factor automatically changes to 50. So in theory this should now be quantity 1 x 50 = quantity 50.
Looking below, the field “Qty as per Stock UOM” now indicates 50 which is correct. Yet the price isn’t multiplied. Then when I return to the main PO form, it indicates as Quantity 1 with the price of 1 unit and not the price of 1 box (50 x unit price).