After Second_Window.toFront(), Click on First_Window, Event activate is not fire

Hello.

I have two Windows. (Ext.Window)

First_Window,

Second_Window

First_Window ist active.

Then I open the Second_Window. (Second_Window is in Front of First_Window)

Then I click on First_window. Event "activate" is fire, First_Window come to Front.

Now I want, that Second_Window come to Front an I use Second_Window.toFront();

So far everything is OK.

But now, when I click on First_Window, its Event "activate" is not fire.

Can anybody help? I am using ExtJS 5.0.1

After Second_Window.toFront(), Click on First_Window, Event activate is not fire