Reveral of order assigning files to queue

This may have an obvious answer, but I can't seem to find it

When I assign a first batch of files to the queue (highlight in blue, then drag down) they appear in the correct top to bottom order (meaning the same order as within the folder). Yet when I add a second batch of files from a different folder to the list, the order becomes reversed in the queue. Ex:

original batch:
1-track
2-track
3-track

will look like this in the queue:
3-track
2-track
1-track

Is there an obvious way to drag them down in the correct order? I'm looking at a large number of files spread over many folders, so being able to do this would save a great deal of time over dragging each file one by one.

Many thanks for your help!