Multiple issues with WinRT app using Qt 5.15.8

Hello!

I would like to report mulptiple issues with WinRT app using Qt 5.15.8. First of all, when I add the combobox with some elements and try to select one item using activated signal, it does not select, old item is still selected. Also, the main page (widget) becomes blocked and I can not select any widgets. For example: when I resize the dialog after a while, the combobox item gets selected and window becomes unblocked.

Second issue is when I add second dialog (page), open and close it. The second dialog window title is still set. I want to change it with setWindowTitle("Main page") method but it does nothing. The old (second) dialog title is still displayed. It seems that the window title does not updates when I navigate between dialogs (pages).

Third issue is when I try to change/set the window titlebar color. The program just crashes. 

#include <winrt/Windows.System.Diagnostics.h>
#include <winrt/Windows.UI.ViewManagement.h>
#include <winrt/Windows.Foundation.h>

using namespace winrt;
using namespace Windows::System::Diagnostics;
using namespace Windows::UI;
using namespace Windows::UI::ViewManagement;
using namespace Windows::Foundation; 

auto titleBar = ApplicationView::GetForCurrentView().TitleBar();
titleBar.BackgroundColor(ColorHelper::FromArgb(255, 54, 60, 116));
titleBar.ForegroundColor(ColorHelper::FromArgb(255, 232, 211, 162));

 
I have created and attached the following screenshot:

Qt-Win-RT-app-issue.gif

It just a simple app, I can create a small example for each issue if it is required? Please, fix these issues. Thank you.