Cant change the size of pyside widgets like in maya/nuke

I have a Pyside gui that is used across dccs, maya and nuke, I'm looking to bringing it over to substance. Whatever I try, I cannot change the size of widgets. 

I have tried setFixedHeight(), setGeometry() and setMinimumHeight()

I can use the below code to alter them in maya and nuke, but substance seems to override it with its own custom values. Any ideas?

class MyWindow(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super(MyWindow, self).__init__(parent)

        self.setGeometry(100, 100, 400, 300)  # (x, y, width, height)
        
        # Create a line edit
        self.line_edit = QtWidgets.QLineEdit("Yo!", self)
        
        # self.line_edit.setGeometry(0, 0, 200, 80)  
        # self.line_edit.setFixedSize(200, 80)  
        self.line_edit.setMinimumHeight(200)  

Thanks!