My golly, Kobo doesn't have a strong track record when it comes to systems changes so I hope this progresses smoothly .......
Like others have mentioned, I can't work out the order of books shown when I click on the 'Author' arrow, for both ascending and descending.
I can appreciate that 'Status' moves those yet to be purchased books, eg previews, to the top of the list, and series seems to be a subset of (in my case) 'Author'. (But 'Author' is not in alpha order, just a mish mash of alpha listings!)
And for the same account, new format I have 249 books, old format 242, the difference being 7 I can't really account for because there are 9 previews in the new format.
Edit
Oh, and my Purchase History for that same account shows 196 purchases, with the difference being over 50 books. Maybe the difference relates to 'freebies' but I don't download freebies very often. Who knows!!