[Edit: never mind, there is a new issue with scene unloading] We have 2 buttons stacked on top of each other. One is always deactivated. In 5.1.1f1 we do this so that we can toggle the button appearance. In 5.3.0f2 we can get into a state where the deactivated button receives a click callback but the activated one does not. Was there an API change with events and deactivated objects? We deactivate the parent of the buttons, not the buttons themselves.