Adding an additional line during an inventory transaction

Hello, we have the following scenario where the user creates multiple lines during a miscellaneous transaction. the issue is that when we are adding additional line, the new line has a number 1 for example instead of number 2. In other words, they are not cumulative which makes it harder for the user to track the On-hand quantity since the field is in the bottom of the page.

Is there any workaround for it?