How to send a WM_MOUSELEAVE message to the WebView2 control

[xland]

In a C++ WebView2 project, when my WebView2 control occupies the entire area of the parent window,
how can I send a WM_MOUSELEAVE message to the WebView2 control when the mouse leaves the window?

I tried to track mouse leave events in the main window by handling WM_MOUSEMOVE :

TRACKMOUSEEVENT tme;
tme.cbSize = sizeof(tme);
tme.dwFlags = TME_LEAVE;
tme.hwndTrack = m_appWindow->GetMainWindow();
tme.dwHoverTime = 0;
::TrackMouseEvent(&tme);

And I attempted to send a WM_MOUSELEAVE message to the WebView2 control in the main window's WM_MOUSELEAVE handler like this:

auto m_compositionController = this->ctrl.try_query<ICoreWebView2CompositionController>();
m_compositionController->SendMouseInput(
    static_cast<COREWEBVIEW2_MOUSE_EVENT_KIND>(WM_MOUSELEAVE),
    static_cast<COREWEBVIEW2_MOUSE_EVENT_VIRTUAL_KEYS>(GET_KEYSTATE_WPARAM(wParam)),
    mouseData, point);

However, I found that since the WebView2 control occupies the entire area of the parent window, the parent window never receives the WM_MOUSEMOVE message at all.
So the parent window also doesn't receive the WM_MOUSELEAVE message.
What should I do?