一个在另一个上面的图像按钮不能单击另一个下面的那个 - Scene2d LIBGDX

I have two ImageButtons one on top of the other. Depending on events in my game I fadeOut one of the buttons and fadeIn the other, and vice versa. The problem is that the buttons are placed in a Stack at exactly the same position and the button underneath does not receive the click event. How can I temporarily stack it on top of the other one that is fadedOut so it receives the click event? one on top of the other