Kage Powers do not decrease chakra cost at all

Despite the message that says "-50% chakra cost" when you turn on powered, there is no decrease in chakra cost whatsoever. I tested it. I used a jutsu - it cost 49 chakra. I turned on powered. I used the same jutsu. It still cost 49 chakra. I also tested it with another jutsu. Same result.

This was for Hokage powers, but I've experienced the same thing with Kazekage powers in the past. I don't know if SL powers have the same issue or not.