Sorry, I don’t know the answer - but you’ve certainly posted in the right place, and someone who does will respond.
I think (and hope!!) that you’ve said the opposite, there, to what you meant to say?
It would make no sense to open long trades when you’ve already opened one and the price moves against you by falling.
That’s the time to let your stop-loss take you out of the trade, because your entry was bad (which happens to all of us, sometimes).
The last thing you’d want to do is to increase your position-size when the price is moving against you!!
If you open another trade under those conditions, a short trade would usually be preferable.
I think (and hope!!) you meant to say that you’re scaling in by adding to positions which are already in profit: that’s a very good idea, and can be a way to maximize profit without increasing risk - which is obviously a good principle! - but that’s exactly the opposite to what you actually said. 
