Thank you for the feedback. Could it be that you mean level 4? If so, the top button opens the door only for 2 seconds after being pressed. This means you have to make sure that you press it at the end of lets say A’s turn and be ready to instantly walk through in B’s turn… Pressing it too early will make the 2 second timer run out before you can enter with B. And trying to walk in with C after pressing the button with A won’t work since skipping B’s turn will cost you 5 seconds aswell…
If you actually mean in level 3, then that is very odd, since there were was never any bug with buttons not working…