DevicePicker fails to display at the correct coordinates when DPI != 96

I've been struggling with this issue for several days and haven't found a solution despite consulting numerous documentation sources.

I'm attempting to invoke DevicePicker.show() to display the DevicePicker at my mouse cursor position. When Windows display scaling is set to 100% (DPI = USER_DEFAULT_SCREEN_DPI), it works perfectly and appears near the cursor. However, with any other scaling setting (DPI != USER_DEFAULT_SCREEN_DPI), there's a consistent offset between the displayed position and the coordinates I provide.

Following the guidance at https://learn.microsoft.com/en-us/windows/win32/learnwin32/dpi-and-device-independent-pixels, I'm converting the mouse cursor position through DPI scaling before passing it to DevicePicker.show():

void ShowPicker(HWND hwnd, Rect rect) {
    DevicePicker devicePicker;
    wprintf(L"Picker: X=%f Y=%f Width=%f Height=%f\n", rect.X, rect.Y, rect.Width, rect.Height);
    //devicePicker.as<IInitializeWithWindow>()->Initialize(hwnd);
    devicePicker.Show(rect);
}

void ShowPosition(HWND hwnd) {
    POINT pt = {};
    GetCursorPos(&pt);

    // Show picker at cursor position
    // DevicePicker expects screen coordinates in physical pixels
    float scale = static_cast<float>(GetDpiForWindow(hwnd)) / USER_DEFAULT_SCREEN_DPI;
    wprintf(L"scale = %f\n", scale);
    Rect pickerRect;
    pickerRect.X = static_cast<float>(pt.x) / scale;
    pickerRect.Y = static_cast<float>(pt.y) / scale;
    pickerRect.Width = 0.0;
	pickerRect.Height = 0.0;
    ShowPicker(hwnd, pickerRect);
}

At 100% Windows scaling (scale=1), this works correctly. However, at 200% scaling (scale=2), there's already a significant deviation from the expected position.

Here is full code:

#include "framework.h"
#include "device_picker.h"
#include <cstdio>
#include <stdexcept>
#include <shobjidl_core.h>
// NuGet CppWinRT 2.0.250303.1
#include <winrt/base.h>
#include <winrt/Windows.Devices.Enumeration.h>
#include <winrt/Windows.Media.Audio.h>
using namespace winrt;
using namespace winrt::Windows::Devices::Enumeration;
using namespace winrt::Windows::Foundation;
using namespace winrt::Windows::Media::Audio;
void RegisterClass(HINSTANCE hInstance, PCWSTR class_name);
HWND CreateMainWindow(HINSTANCE hInstance, PCWSTR class_name);
void MessageLoop();
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);
int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
                     _In_opt_ HINSTANCE hPrevInstance,
                     _In_ LPWSTR    lpCmdLine,
                     _In_ int       nCmdShow)
{
    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);
	// Create console for debug output
    AllocConsole();
    FILE* file;
    freopen_s(&file, "CONOUT$", "w", stdout);
    freopen_s(&file, "CONOUT$", "w", stderr);
	wprintf(L"Console initialized.\n");
    // Initialize random seed
    srand(static_cast<unsigned int>(time(nullptr)));
    // Set DPI awareness
    SetProcessDpiAwarenessContext(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
    // Initialize WinRT
    init_apartment();
    LPCWSTR windowClass = L"demo_window_class";
    try
    {
        RegisterClass(hInstance, windowClass);
        HWND hwnd = CreateMainWindow(hInstance, windowClass);
        MessageLoop();
    }
    catch (const std::exception& ex)
    {
        MessageBoxA(nullptr, ex.what(), "Error", MB_ICONERROR);
        return 1;
    }
    return 0;
}
void RegisterClass(HINSTANCE hInstance, PCWSTR class_name) {
    WNDCLASSEXW wc;
	memset(&wc, 0, sizeof(wc));
    wc.cbSize = sizeof(WNDCLASSEXW);
	wc.hCursor = LoadCursor(nullptr, IDC_ARROW);
	wc.hInstance = hInstance;
	wc.lpszClassName = class_name;
	wc.style = CS_HREDRAW | CS_VREDRAW;
	//wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1); // White background
	wc.lpfnWndProc = WndProc;
	ATOM atom = RegisterClassExW(&wc);
	if (atom == 0) throw std::runtime_error("Failed to register window class");
	
}
HWND CreateMainWindow(HINSTANCE hInstance, PCWSTR class_name) {
	PCWSTR window_title = L"Device Picker Sample";
    int screen_width= GetSystemMetrics(SM_CXSCREEN);
	int screen_height = GetSystemMetrics(SM_CYSCREEN);
    int x = 0;
    int y = 0;
	int w = screen_width;
	int h = screen_height;
    HWND hwnd = CreateWindowExW(
        0,
        class_name,
        window_title,
        WS_POPUP | WS_VISIBLE,
        x, y, w, h,
        nullptr,
        nullptr,
        hInstance,
        nullptr
	);
    if (hwnd == nullptr) throw std::runtime_error("Failed to create main window");
	ShowWindow(hwnd, SW_SHOW);
	UpdateWindow(hwnd);
	return hwnd;
}
void MessageLoop() {
    MSG msg;
    while (GetMessage(&msg, nullptr, 0, 0)) {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
	}
}
void ShowPicker(HWND hwnd, Rect rect) {
    DevicePicker devicePicker;
    wprintf(L"Picker: X=%f Y=%f Width=%f Height=%f\n", rect.X, rect.Y, rect.Width, rect.Height);
    //devicePicker.as<IInitializeWithWindow>()->Initialize(hwnd);
    devicePicker.Show(rect);
}
void PaintRect(HWND hwnd, RECT rect) {
    wprintf(L"Painting: left=%d top=%d right=%d bottom=%d\n", rect.left, rect.top, rect.right, rect.bottom);
    HDC hdc = GetDC(hwnd);
    if (hdc == nullptr) {
        wprintf(L"GetDC failed\n");
        return;
    }
    // Random color (RGB only, alpha 0)
    COLORREF color = RGB(rand() % 256, rand() % 256, rand() % 256);
    HBRUSH hBrush = CreateSolidBrush(color);
    FillRect(hdc, &rect, hBrush);
    DeleteObject(hBrush);
	ReleaseDC(hwnd, hdc);
}
void ShowPosition(HWND hwnd) {
	// This function shows both cursor position and picker position for comparison
    const int WIDTH = 100;
    const int HEIGHT = 100;
    POINT pt = {};
    if (!GetCursorPos(&pt))
    {
        wprintf(L"GetCursorPos failed\n");
        return;
    }
    POINT clientPt = pt;
    if (!ScreenToClient(hwnd, &clientPt))
    {
        wprintf(L"ScreenToClient failed\n");
        return;
    }
    wprintf(L"ScreenCursor: X=%d Y=%d\n", pt.x, pt.y);
    wprintf(L"ClientCursor: X=%d Y=%d\n", clientPt.x, clientPt.y);
    // Show picker at cursor position
    // DevicePicker expects screen coordinates in physical pixels
    float scale = static_cast<float>(GetDpiForWindow(hwnd)) / USER_DEFAULT_SCREEN_DPI;
    wprintf(L"scale = %f\n", scale);
    Rect pickerRect;
    pickerRect.X = static_cast<float>(pt.x) / scale;
    pickerRect.Y = static_cast<float>(pt.y) / scale;
    pickerRect.Width = 0.0;
	pickerRect.Height = 0.0;
    ShowPicker(hwnd, pickerRect);
	// Draw a rectangle around the pointer, centered on the pointer
    RECT paintRect;
    paintRect.left = clientPt.x - (WIDTH / 2);
    paintRect.top = clientPt.y - (HEIGHT / 2);
    paintRect.right = clientPt.x + (WIDTH / 2);
    paintRect.bottom = clientPt.y + (HEIGHT / 2);
    PaintRect(hwnd, paintRect);
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    LRESULT res = 0;
    switch (message)
    {
    case WM_LBUTTONDOWN:
    {
        wprintf( L"WM_LBUTTONDOWN: wparam(0x%llX) lparam(0x%llX)\n",
            static_cast<unsigned long long>(wParam),
            static_cast<unsigned long long>(lParam));
		// Click left mouse button to show device picker
        ShowPosition(hwnd);
        break;
    }
    case WM_RBUTTONDOWN:
    {
		// Right mouse button to quit application
        PostQuitMessage(0);
		break;
    }
    case WM_KEYDOWN:
    {
        wprintf(L"WM_KEYDOWN: wparam(0x%llX) lparam(0x%llX)\n",
            static_cast<unsigned long long>(wParam),
            static_cast<unsigned long long>(lParam));
        // Handle ESC key to quit application
        if (wParam == VK_ESCAPE)
        {
            PostQuitMessage(0);
        }
        break;
    }
    default:
        res = DefWindowProcW(hwnd, message, wParam, lParam);
        break;
    }
    return res;
}