You have the "Lock panel until handler completes" option activated for the Event case you created. Right-click on the Event title and disable that option on the pop-up menu. Your panel will then behave as you expect.
Since you have a while loop inside the event handler, the panel is locked when you first click the boolean.
Keep playing with that event structure. It is most powerful! You might want to think about using it in tandem with a state machine.
Daniel L. Press
PrimeTest Corp.
www.primetest.com