Property in PropertyGrid is not updated until focused manually

Hello,

I am trying to update a property value from a Form dialogue. This form dialogue is opened in the DoWork method ofBackgroundWorker. 

I have a custom type editor to update the property in the question.

Here is my code:

class UIFocusTracingEditor : UITypeEditor
    {
        public override System.Drawing.Design.UITypeEditorEditStyle GetEditStyle(System.ComponentModel.ITypeDescriptorContext context)
        {
            if (context != null)
            {
                return System.Drawing.Design.UITypeEditorEditStyle.Modal;
            }
            return base.GetEditStyle(context);
        }

        public override object EditValue(System.ComponentModel.ITypeDescriptorContext context, IServiceProvider provider, object value)
        {
            if (value is string || value == null)
            {                               
                BackgroundWorker worker = new BackgroundWorker();
                worker.DoWork += new DoWorkEventHandler(worker_DoWork);
                worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);

                worker.RunWorkerAsync(context);                   
            }
            return base.EditValue(context, provider, value);
        }

        private void worker_DoWork(object sender, DoWorkEventArgs e)
        {
            ITypeDescriptorContext context = (ITypeDescriptorContext)e.Argument;

            using (var mw = new MainWindow())
            {

                var result = mw.ShowDialog();

                if (result == DialogResult.OK)
                {
                    string[] items = mw.targetItemPath.Split(';');

                    string[] arr = mw.targetItemPath.Split(';');
                    Array.Reverse(arr);
                    mw.targetItemPath = string.Join(";", arr);//Update the proeprty
                    ((ITargetElementPath)context.Instance).TargetElementPath = mw.targetItemPath;
                }
            }
        }

        void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            //CommandManager.InvalidateRequerySuggested(); //not working
        }

        void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            
        }
    }

    public interface ITargetElementPath
    {
        string TargetElementPath { get; set; }
    }

I hope you understand the code. In above code, TargetElementPath is the property which I want to update.

As suggested by someone on stackoverflow, I tried  CommandManager.InvalidateRequerySuggested() to focus on the property in PropertyGrid. But it didn't work.

Could you please tell me the right solution?

Thank you in advance!