[WillW]

Well that's my point - there is no Collections option under "Filter". I can choose Collections under "Sort" - OR I can choose Recent under "Sort". I used to be able to choose Recent for Collections, and they would show in order of most recently accessed. With this option, no books would show until I opened a collection All my books are in collections.
The only option for Recent now shows a few Collections in recent order, followed by pages and pages of books before the next collection shows up. If I want only Collections to show on Library page, they will only show in alphabetical order. It's not an enormous issue, but I have a lot of them and it's convenient to have them in order of most recent.