It can't speed stuff up if an action is already playing, which is probably what's happening here. I know that you have to wait to get to the command menu in a fight to activate it, for example.Not sure if anyone has brought this up, but if you try to enable or disable speed up as dialogue starts or stops. (Sometimes even mid-way through.) The game will just freeze. Also I'm not sure if it's intended or not, but you're unable to enable speed up if you've already started a battle. I double-checked with a fresh version of v21.1 essentials, and the outcome was the same.