Personally I would say its just the unresponsiveness of some actions comes from the animation when assigning turns to last like over a second where it feels it takes a long time to assign and remove actions. Another part is that you cant skip through the 3 stars menu by clicking. I felt the same way that is was clunky at first even though replaying it most actions were instant so the animation is my best guess as to where that feeling arose. Never had any issues with the UI buttons tho