I tried adding a book via the Epilogue app on iPhoneOS. Didn’t come up in results, then it did via ISBN, then not, then it did again. I added it. The book count went up and when I search for the book on the Bookshelf in a browser, it’s now there several times, marked ‘Read’ (which is the right shelf). But it’s not in any version of the Bookshelf, either in browser or or Epilogue.
Something’s up here, and I just thought I’d flag it.