Not sure if other people use it this way, but we pick by order number.
We use the Dispatch Console to scan products and process. This works well, until you start merging orders.
Obviously a merged order is given a new order number, which might be a lot on from what we've picked. Because Dispatch Console chooses which order you should be processing by the date and time, if often chooses the merged order, even though you haven't picked it.
My suggestion is the have a tick box of 'process by order number', and have Dispatch Console choose the order with the lowest order number, rather than date and time.