createWindowContainer doesn't work when I set FramelessWindowHint and WA_TranslucentBackground

[wali]

QtWidgets.QWidget.createWindowContainer(QtGui.QWindow.fromWinId(hwnd)) doesn't work when I set
setWindowFlag(QtCore.Qt.FramelessWindowHint)
setAttribute(Qt.WA_TranslucentBackground)
It seems it needs a Background to display another window, does anyone have another solution? The purpose when I use FramelessWindowHint and WA_TranslucentBackground is to round the corner of QMainWindow.

[SGaist]

Hi and welcome to devnet,

Which version of PySide6 / PyQt6 are you using ?
On which OS ?

Can you provide a minimal script that shows this behavior ?