Off the top of my head - a python app for drawing over a macos screen, but it used an API which didn't support transparent windows, I could draw over a black screen which was so close in code (even set the background alpha) but miles from the desired application. And a Java android app for viewing an external camera, which it seems used an API that doesn't support external cameras.
Of course, because it's not sentient when a couple of days later I figure out from searching elsewhere why it's effort would never work and tell it why, it just apologises and tells me it already knew that. As I'm going along though telling it what errors I'm getting it keeps bringing up alternative solutions which again look like exactly what I want but are completely broken.
I haven't had it produce a single thing that was any use to me yet, but so often it looks like it's done something almost magical. One day I'm sure it'll get there, in the meantime I'm learning to loathe it.
Separately, I've asked it to create a job advert for a role in my wife's business and it did a decent job of that, but it's far easier to walk a path there from what it provides to an acceptable solution. Programming is hard.