It's 04:00 here, and I am too tired to think straight, apologies if I have missed the answer:

. I've copied 5 series over to my wife's 2nd gen Paperwhite from Calibre, a total of around 70 books. All have series order metadata showing in Calibre, but when I open the Paperwhite, they are not in any order at all - I can sort by author, and that's it. Do I have to manually rename all the books in each series with a leading number?