I’m creating a big slideshow for a talk and I’m doing it by creating albums for the different sections / topics. The plan was then to drag them all into a single slideshow once the structure is finalised.

So I drag files in from Album A into the slideshow and they appear in date order. I drag them into the order I want and the order indicator changes from Date to Manual. Good. I now anticipate that the next album’s worth dragged in will appear in the order of the source album. No such luck - they appear in random order after - at least neither version number nor date order. At least they don’t mix in with the first batch. Any ideas? This is quite a big project so  don’t want to create a monster slideshow straight off.