Foreground service stops when I disconnect phone from computer.

I'm working on an app that takes the GPS position every minute. I tested it and it worked fine when the phone is connected to the computer. But then I took the phone off, closed it, put it in my pocket and walked around the block to see my trajectory. It turns out that the GPS points were not saved. I saw that the foreground service stops doing periodic task after being disconnected from the PC where I'm developing the app. The service starts working again when I reconnect it.

I tried a few things and I know what it's not:
1) It's not the developer mode. The problem happens when the developer mode is On and Off
2) It's not the android version. I tried 2 different android versions: 6.0 and 8.0
3) It's not the "Enable developer instrumentation (debugging and profiling)" option in the Android Options properties. I tried both ways.
4) It's not the function that I'm calling. I tried placing many different functions (non GPS related) to check if they're even being called. They're never called.
5) It's not a power saver issue. The app is unrestricted when it comes to power use, and this issue still happens when I plug the phone to a charger on a wall.
6) I tried calling the function synchronously and asynchronously. Still the same.

I have the feeling that there's a very basic thing that I'm missing. Maybe something right in front of my nose. In any case, here's the code. If you need more details please let me know.

`
using System;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Support.V4.App;

namespace MyTest.Mobile.Droid.Services
{
[Service]
public class BackgroundService : Android.App.Service
{
static readonly string TAG = typeof(BackgroundService).FullName;
static readonly string CHANNEL_ID = "background_process";
bool isStarted;
Handler handler;
Action gpsRunnable;

    public override void OnCreate()
    {
        base.OnCreate();
        CreateNotificationChannel();
        handler = new Handler();

        gpsRunnable = new Action(() =>
        {
            // [THIS IS WHERE I PUT THE FUNCTION TO BE CALLED]
            if (isStarted)
            {
                handler.PostDelayed(gpsRunnable, 60000);
            }
        });
    }

    public override IBinder OnBind(Intent intent)
    {
        return null;
    }

    public override StartCommandResult OnStartCommand(Intent intent, StartCommandFlags flags, int startId)
    {
        if (intent.Action.Equals(Constants.ACTION_START_SERVICE))
        {
            if (!isStarted)
            {
                RegisterForegroundService();
                handler.PostDelayed(gpsRunnable, Constants.DELAY_BETWEEN_BACKGROUND_OPERATIONS);
                isStarted = true;
            }
        }
        else if (intent.Action.Equals(Constants.ACTION_STOP_SERVICE))
        {
            StopForeground(true);
            StopSelf();
            isStarted = false;
        }
        return StartCommandResult.Sticky;
    }

    void RegisterForegroundService()
    {
        var notification = new NotificationCompat.Builder(this, CHANNEL_ID)
            .SetContentTitle(Resources.GetString(Resource.String.app_name))
            .SetContentText(Resources.GetString(Resource.String.notification_text))
            .SetSmallIcon(Resource.Drawable.ic_stat_name)
            .SetContentIntent(BuildIntentToShowMainActivity())
            .SetOngoing(true)
            .Build();
        StartForeground(Constants.SERVICE_RUNNING_NOTIFICATION_ID, notification);
    }

    PendingIntent BuildIntentToShowMainActivity()
    {
        var notificationIntent = new Intent(this, typeof(MainActivity));
        var pendingIntent = PendingIntent.GetActivity(this, 0, notificationIntent, PendingIntentFlags.UpdateCurrent);
        return pendingIntent;
    }

    public override void OnDestroy()
    {
        handler.RemoveCallbacks(gpsRunnable);
        var notificationManager = (NotificationManager)GetSystemService(NotificationService);
        notificationManager.Cancel(Constants.SERVICE_RUNNING_NOTIFICATION_ID);
        isStarted = false;
        base.OnDestroy();
    }

    void CreateNotificationChannel()
    {
        if (Build.VERSION.SdkInt < BuildVersionCodes.O)
        {
            return;
        }

        var name = Resources.GetString(Resource.String.channel_name);
        var description = GetString(Resource.String.channel_description);
        var channel = new NotificationChannel(CHANNEL_ID, name, NotificationImportance.Default)
        {
            Description = description
        };

        var notificationManager = (NotificationManager)GetSystemService(NotificationService);
        notificationManager.CreateNotificationChannel(channel);
    }

}

}

`