Fullscreen QML application window no repaint - ALT+TAB and windows key

Hello, first I want to thanks very much for Qt framework ! It's amazing.

My application work on FullScreen, on my Linux pc and everything work perfect, but after release application on Windows OS, main window of application was disappear after show QML Dialog. I skipped this problem by workaround in this bug report (Fullscreen QML application flickers if dialog is shown). So best way is to use only Qt solutions (Popup, not OS dialogs)

Unfortunately, there is still a problem with the operation of the application when using the ALT + TAB shortcut or after dropping the application onto the beam using the Windows key.

• combination of ALT + TAB, causes that we move to the system, unfortunately the main application window is still visible and covers the whole desktop. Although using the mouse you do not click on the items in the application but on the desktop. Only next using the ALT + TAB key combination causes the main window is active again.
• after dropping the application onto the bar (Windows key), the application window disappears. When you try to restore the application, it returns to the screen (because you can click on its items) but the application window is not visible. It probably does not repaint.

The situation looks like it does not appear on every computer. I ran it on 6 computers with Windows systems and on 4 of them this problem occurred. Systems on which the application worked correctly: Windows 10, Windows Server 2019. Systems on which the window was not repaint: Windows 7 and Windows 10.

I give the small application source code