How to fix the "one time use" radio button in C++ Win 32

Question

Im developing a program on window using only Win32 Api (so no .Net or win form here) and when testing the radio button on my program, i noticed that the radio button is one time used. i set each of the radio button to change the title to diffrent name if you press it back and forward multiple times but when i tried to do that it only change the title once. heres the minimal reproducible sample:

#include <Windows.h>
#define RDCC1 1001
#define RDCC2 1002
#define DEFRADIOBUTTONSIZEX     200
#define BUTTONSTYLE             WS_VISIBLE | WS_CHILD
#define DEFRADIOBUTTONSIZEY     20
#define MAINWINDOWX             800
#define MAINWINDOWY             600
#define MAINWINDOWSTYLE         WS_OVERLAPPED| WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX | WS_MAXIMIZEBOX

LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp)
{
    HWND clckinerval = nullptr;
    HINSTANCE hinst = GetModuleHandle(0);
    int tempsw = 0;

    auto add = [&](const wchar_t* name, int id, int x, int y, int w, int h, bool first = false)
    {
        DWORD style = WS_VISIBLE | WS_CHILD | BS_AUTORADIOBUTTON;
        if (first) style |= WS_GROUP | WS_TABSTOP;
        return CreateWindowEx(0, L"Button", name, style,
            x, y, w, h, hwnd, (HMENU)id, hinst, NULL);
    };
    switch (msg)
    {
    case WM_CREATE:
    {
       
        HWND radio1 = add(L"RD1", RDCC1, 17, 30, 200, 20, true);
        HWND radio2 = add(L"RD2", RDCC2, 17, 51, 200, 20);

        SendMessage(radio1, BM_SETCHECK, BST_CHECKED, TRUE);

        
        break;
    }
    case WM_COMMAND:
    {
        switch (wp)
        {
        case RDCC1:
        {

            SetWindowText(hwnd, L"Hello");
        }
        case RDCC2:
        {
            if (tempsw == NULL) {
                SetWindowText(hwnd, L"Hello");
                tempsw = 1;
            }
            else
            {
                SetWindowText(hwnd, L"Bye");
            }


        }
        UpdateWindow(hwnd);
        break;
        }
    }
    case WM_PAINT:
    {
        PAINTSTRUCT ps;
        HDC hdc = BeginPaint(hwnd, &ps);
        FillRect(hdc, &ps.rcPaint, (HBRUSH)(COLOR_WINDOW));
        EndPaint(hwnd, &ps);
        break;
    }
    case WM_DESTROY:
    {
        PostQuitMessage(0);
        break;
    }
    }
    return DefWindowProc(hwnd, msg, wp, lp);

}
int WINAPI wWinMain(HINSTANCE hinst, HINSTANCE hiprevinst, PWSTR nCmdLine, int ncmdshow)
{
    const wchar_t CLASS_NAME[] = L"Send help i spend too much on this";
    WNDCLASS wc = { };
    wc.lpfnWndProc = WndProc;
    wc.hInstance = hinst;
    wc.lpszClassName = CLASS_NAME;
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    RegisterClass(&wc);
    HWND hwnd = CreateWindowEx(0, CLASS_NAME, L"Sample", MAINWINDOWSTYLE, CW_USEDEFAULT, CW_USEDEFAULT, MAINWINDOWX, MAINWINDOWY, NULL, NULL, hinst, NULL);
    ShowWindow(hwnd, ncmdshow);
    MSG msg;
    while (GetMessage(&msg, NULL, NULL, NULL))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return 0;
}