This was discussed some time ago and the answer was that SE runs simulations that are different every time (there must be some randomness in evaluating moves).
That’s a visual aid to see squares for points and it can be useful, but the problem we are discussing here is exactly that score doesn’t correspond to the area after you click on the board.
If you want something meaningful you have to previously add endgame moves (closing borders) and then run SE without touching anything.
But the expected behaviour was to click on stones to change their life/death status. That doesn’t work.