Pegging shows onhand in the same lot getting split for the same end demand

Summary:

We have part#X that needs part#Y for 2 per top level . There is a WO for X for qty 24 and there is Onhand for Y for 200 with the same Lot# in the same subinv and locator. There is a WO demand of 48 for part Y and the pegging for it shows two Onhand records for Y for the same lot and one is for 32 and the other is for 16.Why would supply planning not have just one OH record of 48 pegging to the WO demand instead of creating one for 32 and another