User has found that when copying a PO Line, that the Price field is not copied from the source PO Line, nor is the Unit of Measure. This leaves the Price in "each", despite the Purchase (quantity) having the source PO Line's unit of Measure. Not only does the Price UOM not match the Purchase UOM, it is not changeable.
Reported as a bug, VSTS#562861.
Workaround: The Price UOM can be updated if you change the Purchase Type of the PO Line and change it back immediately.
SR7001211770