Along_the_Wire …how do you mean re-order, you mean drag them into a different sequence, or have them go 99-1 rather than 1-99?
If it’s the latter, like Dutchy says you click the hashtag symbol at the top of the playlist and it should reverse the order.
As long as you are filtering via the number (ie. hashtag selected), you should be able to drag tracks into any order you like, but if you have a different filter criteria selected (BPM, Comments etc.), it won’t let you drag/reorder.
None of this necessarily reflects what you see on the CDJ/controller though, it’ll depend what search filter you have selected on there.