When you create a sales order in Springboard and add items to it either by scanning or via the Find item lookup, we split the same item onto multiple lines to more easily allow retailers to "split" the order to multiple fulfillment locations.
However, split lines cannot be filled simultaneously from the same fulfillment location. If you need to fulfill multiple quantities of the same item from a single location, you need to consolidate multiple quantities of the same item onto a single line on the sales order by manually incrementing the quantity of the line that you are ordering more than one of. (This actually should be quicker when creating than order than adding each item successively via the Find lookup.)
If you have an existing sales order that you need to correct, you can go back to the sales order and press the "Edit" button. You should delete excess lines, combine duplicate items into one line and then reopen the order. You will then be able to fulfill it from a single fulfillment location.