You may have missed a step. If you could explain the steps you followed, might be able to understand the issue. The standard process is;
Create the Production Order -> Select the Source No. (Item Number) in the Header -> Update the Quantity in the Header -> Select the Due date -> *Refresh Production Order*
That should populate the production lines for you. I see quantity difference in your header and line, did you insert the lines manually ?
If you run the "Refresh Production Order.." process, that should update your lines correctly.
