This isn’t reasoning at all. It’s applying a well known algorithm to a problem. It literally says “classic” in its response.
Is your reasoning always perfect? No? Ever get partial credit on a test question in school? Yes? Well, maybe don't expect perfection from a model that didn't exist 5 years ago, that was considered impossible 10 years ago, and that would have gotten you burned as a witch 15 years ago.
Nobody claims that o3-pro is AGI, or even that it is going to lead up to AGI.