Issue with Samsung Note 8 running Android 7.1

My app invokes Call Phone intent. There is no problem with Marshmallow phones previously. But now on Note 8 I tried it for the first time. When I invoke the Call Phone intent I get the following Exception.Message.

Permission Denial: starting Intent { act=android.intent.action.CALL dat=tel:xxxxxxxxxx cmp=com.android.server.telecom/.components.UserCallActivity launchParam=MultiScreenLaunchParams { mDisplayId=0 mBaseDisplayId=0 mFlags=0 } } from ProcessRecord{7dc990c 19695:Dates2Remember_XFAXU.Droid/u0a327} (pid=19695, uid=10327) with revoked permission android.permission.CALL_PHONE

A snip of my app's project properties is attached which shows that the Target version is set to 7.1 and the CALL_PHONE requirement is checked.

I am using dependency service. The dependant Android code is shown below. The following may be noted in this regard:

1. Though Forms.Context is obsolete, it still works. However I have tried the other ways to set the Context also tried. The relevant code is commented below the Forms.Context usage.

2. The error occurs at context.StartActivity(intent).

   using Android.Content;
   using Android.Telephony;
   using System;
   using System.Linq;
   using Xamarin.Forms;
   using Uri = Android.Net.Uri;

   [assembly: Dependency(typeof(PhoneDialer.Droid.PhoneDialer))]

   // For this to work ensure .Droid's Project Options -> Build
   // -> Android Application -> Required Permissions -> CallPhone
   // is checked.
   namespace PhoneDialer.Droid
   {
   public class PhoneDialer : IDialer
   {
   //Context context => Plugin.CurrentActivity.CrossCurrentActivity.Current.Activity;

       // Dial the phone
       public bool DialFromDevice(string number, string displayName)
       {
           bool rtn_value = false;
   
           try
           {
               var context = Forms.Context;
               //Context context = Android.App.Application.Context;
               //var context = MyApp.Droid.MainActivity.instance;
   
               if (context != null)
               {
                   var intent = new Intent(Intent.ActionCall);
                   intent.SetData(Uri.Parse("tel:" + number));
   
                   if (IsIntentAvailable(context, intent))
                   {
                       context.StartActivity(intent);
                       rtn_value = true;
                   }
               }
           }
           catch (Exception ex)
           {
               System.Diagnostics.Debug.WriteLine("Error: {0}", ex.Message);
               rtn_value = false;
           }
   
           return rtn_value;
       }
   
       // Checks if an intent can be handled.
       public static bool IsIntentAvailable(Context context, Intent intent)
       {
           var packageManager = context.PackageManager;
   
           var list = packageManager.QueryIntentServices(intent, 0)
               .Union(packageManager.QueryIntentActivities(intent, 0));
           if (list.Any())
               return true;
   
           TelephonyManager mgr = TelephonyManager.FromContext(context);
           return mgr.PhoneType != PhoneType.None;
       }
   }
   

   }

No issue with even Marshmallow simulator for VS. My Note 8 is still at API 25. It appears the project context is not passed on properly. Am I doing anything wrong?

Note: Unfortunately here if you employ multiple modes of formatting something will not presented correctly as required. Any suggestions to correct it, form myside, are welcome.