Setting testAttribute(Qt::WA_UnderMouse) should consider that the control is already under the mouse

Steps to reproduce:
1. Move the mouse to the button, the value obtained by testAttribute(Qt::WA_UnderMouse) is true;
2. Use the timer to modify the WA_UnderMouse value of this widget to false;
3. Click the button again, the value of WA_UnderMouse is still false, this time the button is under the mouse;   see error.mp   and  demo
4. When the mouse moves and enters the button again, the value of WA_UnderMouse is true

expect:
As long as the widget is under the mouse, the value of WA_UnderMouse is always true.