Qt5 modal widget stuck behind main window on Linux(buster)

[Nata1ie]

[Qt5 modal dialogs stuck behind main window](seems like its hanging)
I already tried:
warning = new QWidget(wdcentral);
warning->setWindowModality(Qt::WindowModal);
warning->setWindowFlags(Qt::Window | Qt::FramelessWindowHint | Qt::WindowStaysOnTopHint);

Note it works in prev version of Debian (strach + Qt5).

I've found in forum 2014 the solution:
warning->setWindowFlags(warning->windowFlags() | Qt::Window | Qt::FramelessWindowHint | Qt::WindowStaysOnTopHint);
it does not work neither.

Please help me, is there a workaround?

[Max1971]

Hi,
i have the same different problems some years ago, and i have to manage myself with code.

I get a good solution for me setting for QMainWindow the following flags

appWindow->setWindowFlags(Qt::Window | Qt::WindowStaysOnBottomHint);

For a QDialog

d->setWindowFlags(Qt::Window | Qt::CustomizeWindowHint | Qt::WindowTitleHint);

To manage the fact the dialog is modal i don't use the flag QT:WindowModal but i write a method where i disable
application manually (menu etc...) until the user don't close o press button on modal dialog