[Reg] QDialog modal dialog event loop not finishing

I have QDialog subclass that implements on close event calls event->accept() and also setResult() to some value.

int value = qtdialog->exec();
// never comes here  when clicking window close button

The same code worked fine from Qt5.x until Qt6.6.2. (I haven't tried 6.6.3), but in 6.7.0 event loop never exits, dialog disappears/gets closed, but event loop remains working.