P. longipetiolatum leaves are clearly different from P. cattleyanum IMO. P. robustum looks very similar to cattleyanum. I don't have P. cattleyanum anymore, but robustum may have a bit thicker and waxier leaves than cattleyanum. I remember cattleyanum being more coreaceous, like the leaves would snap rather than bend. Longipetolatum leaves are rounder and bigger, going to heart shaped on mature plants. Since yours flowered, you'd also have seen long (~1 inch) petioles on the flowers/fruit. My guess is P. robustum, but could be yellow P. cattleyanum.