[Phssthpok]

I have a few collections on my Kindle Oasis: Read, Corrected, PDF, and Catalogue. Until today, these have been the first items on my home screen, followed by my uncollected books in "recent" order. Empty collections did not show up.

Suddenly, for no apparent reason (no firmware updates -- I use the Kindle in Airplane mode at all times to conserve the battery) this has changed.

Empty collections now show up, labelled "no items". When I look at a book in a collection, it appears on the home screen along with my uncollected items instead of staying in the collection. The collections are now also sorted by "recent" order instead of appearing at the top of the first page, so when I upload new books, the collections move down the list and disappear onto the next page.

I have tried "All" vs. "Downloaded" -- no difference. I have tried removing the affected books from the collection they belong to and adding them again, but they still show up mixed in my my uncollected books. I have Filter = Books and Sort = Recent. Changing these makes no difference either. I have tried restarting the Kindle. (I would sacrifice a chicken if I had one.)

Any ideas what has happened, and how I can restore order to the chaos?