EWM Picking Nested HU

Hello, I need some help regarding picking nested HU. I have scenario where the main HU has 5 nested HU. Each one has a quantity in KG and they are all different. I get an ODO created and the WT is also created. The user will scan the nested HU until the quantity is covered. He always remove the whole nested HU. I'm getting an error trying to replicate this. Even adjusting the quantity of the WT with an exception code to match the quantity of two whole nested HU, the system still gives an error. Had anyone have a similar scenario? 

Thanks,