Why does Bluetooth UWP app give access is denied during connection

Question

I am trying to set-up an rfcomm connection with a mobile device and after that I want to set-up hfp service level connection so that I can call from my windows pc and it gives Failed to get

Bluetooth device from ID Bluetooth#Bluetooth00:45:e2:a8:f6:90-48:83:b4:17:24:c2: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))

This error I have already added the bluetooth and bluetooth.rfcomm capability

This is my code:

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using System.Threading.Tasks;
using Windows.Devices.Bluetooth;
using Windows.Devices.Bluetooth.Rfcomm;
using Windows.Devices.Enumeration;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.Networking.Sockets;
using Windows.Security.Authorization.AppCapabilityAccess;
using Windows.Storage.Streams;
using Windows.UI.Popups;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
using Windows.UI.Popups;
using Windows.Security.Authorization.AppCapabilityAccess;
        
// The Blank Page item template is documented at https://go.microsoft.com/fwlink/?LinkId=402352&clcid=0x409
        
namespace hfpuwp
{
    /// <summary>
    /// An empty page that can be used on its own or navigated to within a Frame.
    /// </summary>
    public sealed partial class MainPage : Page
    {
        public static readonly Guid HFP_Id = new Guid("0000111f-0000-1000-8000-00805f9b34fb");
                
        public MainPage()
        {
            this.InitializeComponent();
        }
             
        private async void Button_Click(object sender, RoutedEventArgs e)
        {
            BluetoothDevice BlutooDevice;
            RfcommDeviceService BTService;
            StreamSocket BTSocket;
            DataWriter _writer;
            DataReader _reader;

            DeviceInformationCollection devices = await DeviceInformation.FindAllAsync(BluetoothDevice.GetDeviceSelectorFromPairingState(true));
        
            String xz = "";
            for (int i = 0; i < devices.Count; i++)
            {   
                xz += devices[i].Name+" ";
                //Console.WriteLine(i + "#:    " + devices[i].Name + "    " + devices[i].Id);
                if (devices[i].Name == "OPPO F11 Pro")
                {
                    BTDevice.Text = devices[i].Name + " " + devices[i].Id;
                    try
                    {
                        BlutooDevice = await BluetoothDevice.FromIdAsync(devices[i].Id);
                        var result = await BlutooDevice.GetRfcommServicesForIdAsync(RfcommServiceId.FromUuid(HFP_Id));
                        if (result.Services.Count > 0)
                        {
                            var accessStatus = await BlutooDevice.RequestAccessAsync();
                            BTService = result.Services[0];
                            BTSocket = new StreamSocket();
                            if (result.Services.Count > 0 && accessStatus == DeviceAccessStatus.Allowed) 
                            { 
                                await BTSocket.ConnectAsync(BTService.ConnectionHostName, BTService.ConnectionServiceName,
                                        SocketProtectionLevel.BluetoothEncryptionAllowNullAuthentication);
                            }
                            //_writer = new DataWriter(BTSocket.OutputStream);
                            //_reader = new DataReader(BTSocket.InputStream);
                        }
                        BTDevice.Text = "Connection Sucessful";
                    }
                    catch (Exception ex)
                    {
                        Debug.WriteLine($"Failed to get Bluetooth device from ID {devices[i].Id}: {ex.Message}");
                        continue; 
                    }
                }
            }
        }
    }
}