if you have a trouble with QWebEngineView

[mrhaa]

long story to short,
enable_shadow of PyWindow set to False

[kanslor]

Thank you ! I met the same problem QWebEngineView run slow in PyDracula， your answer works .

Just Change the QWebEngine grphic effect(not use the parent's shadow), and disable it. It performs both PyOneDark and PyDracula

# DROP SHADOW in PyDracula 
self.shadow = QGraphicsDropShadowEffect(self)
self.shadow.setBlurRadius(17)
self.shadow.setXOffset(0)
self.shadow.setYOffset(0)
self.shadow.setColor(QColor(0, 0, 0, 150))
self.ui.bgApp.setGraphicsEffect(self.shadow)

self.ui.webEngineView.setGraphicsEffect(self.shadow)
self.ui.webEngineView.graphicsEffect().setEnabled(False)