QWidget :: createWindowContainer does not support drag and drop (DND) with XWindowSystem

A similar issue has already been raised on Qt4 with QX11EmbedContainer: error report xembed. After switching to the new embedding system (QWindow::fromWinId and QWidget::createWindowContainer) it was not resolved. Has been tested on Qt5 and Qt6. Based on the QWindowContainer sources, the DND event should be dispatched to the original window in the XWindow system through an intermediary created with QWindow::fromWinId. But no events dispatched to the original window through the intermediary using QCoreApplication::sendEvent are passed. Apparently they are not passed to the XWindow by the intermediary. There is also a suspicion that the DND event is not passed to the original window, because there is no handling of these events in QWindow. It is only present in QWidgetWindow. Is there any information on this error? Or maybe there is already a solution to it? Thanks in advance.