Excel Toolbar CommandBarButton Event is not firing in C#

Question

I wrote the following code to capture the click event of Excel's standard toolbar button activated in a C# application.

private void CaptureExcelInteractions()
{
    Excel.Application excelApp = null;

    // Get the process ID of the active window
    IntPtr hwnd = GetForegroundWindow();
    uint processId;
    GetWindowThreadProcessId(hwnd, out processId);

    try
    {
        // Enumerate running Excel processes
        Process[] processes = Process.GetProcessesByName("EXCEL");

        foreach (Process process in processes)
        {
            if (process.Id == (int)processId)
            {
                // This Excel process is the active one
                excelApp = (Excel.Application)System.Runtime.InteropServices.Marshal.GetActiveObject("Excel.Application");
                break;
            }
        }

        if (excelApp == null)
        {
            // No active Excel instance found
            Console.WriteLine("No active Excel instance found.");
            return;
        }
    }
    catch (System.Runtime.InteropServices.COMException ex)
    {
        // Handle exceptions if Excel is not running or not accessible
        Console.WriteLine("Excel is not running or not accessible. Error: " + ex.Message);
        return;
    }

    // Reference the active worksheet
    Excel.Worksheet activeWorksheet = (Excel.Worksheet)excelApp.ActiveSheet;

    // Capture cell changes and subscribe to Excel
    excelApp.SheetChange += (object sh, Excel.Range target) =>
    {
        string cellAddress = target.Address;
        string newValue = (string)target.Text;
        Console.WriteLine($"Cell {cellAddress} changed to: {newValue}");
    };

    
    // Get a reference to the CommandBars
    foreach (CommandBar commandBar in excelApp.CommandBars)
    {
        foreach (CommandBarControl control in commandBar.Controls)
        {
            if (control is CommandBarButton button)
            {
                button.Click += (CommandBarButton ctrl, ref bool cancelDefault) =>
                {
                    string buttonName = ctrl.Caption;
                    Console.WriteLine($"CommandBarButton clicked: {buttonName}");
                };
            }
        }
    }


    // Keep this method running to capture events
    while (isMonitoring && !isPaused)
    {
        // Add a delay or use other mechanisms to keep the method running
        Thread.Sleep(1000);
    }

    Marshal.ReleaseComObject(excelApp);
    // Stop Excel event handling
    excelApp.Quit();
}

However, although the standard toolbar is found, the click event is not executed. This is not an Excel add-in, but a button click event on the existing toolbar. What did I do wrong?

For example, when I click the "Bold" CommandBarButton on the "Font" toolbar, I expect console output to appear, but the click event is not detected.