In Work Order Part list, Component ordered qty getting changed for some component

Hello Experts,

Please need your input on this, When I issue the component in a specific order, so for some component, the ordered qty is changing , means it is observed that if the component is issue from a allocated lot number then it is showing correct ordered qty but when the component is issued from a unallocated lot then new line is created in the part list where order qty is getting subtracted from the original line but not shown in the new line.

example : if for Component ABC i want to issue 500qty for which XYZ lot is allocated in the part list