I think even accepting that Harry Potter’s for kids, Rowling basically figured out how to write in about the 3rd book of the series. Pratchett was pretty much the same, the difference between the first discworld novels which are just pure pastiche and the later ones is enormous, as is the world it all happens in… Not that uncommon where a new author writes in the same world/series.
I can’t think of a third but for me, The Road and Down And Out In Paris and London.
The Road, because for all the bleakness, the characters just miraculously find what they need exactly when they need it. Oh we’re starving and there’s no hope of finding food, oh, here’s some. It lost all sense of jeopardy, which is kind of important. And in the end, nothing actually happens, other than a general wandering through post-apocalyptic cliches.
And Down and Out, because Orwell’s just such a bloody tourist and hypocrite