Rageblade, when fully stacked, will not work on champions who have 3rd hit passives that come from the champion like Jax, and neeko besides the first few hits after being fully stacked. Once it is fully stacked, you can notice that their passive will always proc on the 3rd hit, and not actually take the rageblade into effect. Rageblade will still work on on-hit items, however.
This bug has been happening every time ever since the rageblade change in 9.10, but it was most likely a thing even before then although not as apparent.
Other champions that this could effect the most is Yi, and diana, and possibly more that I forgot about.