GUI MDI Subwindow Only shows on first Button Press

I hope I have a simple question here. I have created a very large GUI with QT Designer and a subwindow for the MDI area. I have used pyuic5 to convert it from a .ui file to a .py file. I have written a function to open that subwindow when a button is pressed. The first time I push the button it works fine. The problem I'm having is the second time the button is pushed it just displays a blank subwindow within the MDI area. How do I get it to display correctly every time the button is pressed. I will attach the code for how I launch the subwindow below. Any advice would be very appreciated. Thank you for your time and your help

Code that is called when button is clicked

def windowaction(self):

    sub = QtWidgets.QMdiSubWindow()
    sub.setWidget(self.Load_Input)
    sub.setObjectName("Load_Input_window")
    sub.setWindowTitle("Load Input")
    self.mdiArea.addSubWindow(sub)
    sub.show()

First time clicking the button

Second time clicking the button

The problem arises from adding the same widget object to different QMdiSubWindow, you must create a new object and add it to the new QMdiSubWindow.

def windowaction(self):
    sub = QtWidgets.QMdiSubWindow()
    Load_Input = LoadInput()
    sub.setWidget(Load_Input)
    sub.setObjectName("Load_Input_window")
    sub.setWindowTitle("Load Input")
    self.mdiArea.addSubWindow(sub)
    sub.show()