While doing WIP Completion through MSCA, cursor is going to Remaining Qty field but not to SN field

 While doing WIP Completion through MSCA, cursor is going to Remaining Qty field but not to SN field after entering the Qty

We are using standard functionality and the order of fields is as follows(see screenshot for more clarity)

Sub

Loc

Qty  :  1(after entering 1 here, the cursor is going to Remaining field but not to SN field due to which user need to manually change the cursor to SN field and then enter serial number which is very tedious process)

Assembly(Disabled field)

SN

Remaining(Disabled field)

What is the easiest way to achieve the cursor movement to go to SN field rather than Remaining field.