How do I update\refresh the same usercontrol used on multiple views

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C#

.NET

WPF

MVVM

I am adding a record from view 2 in the database;
1. The record is inserted successfully and is instantly shown in the usercontrol(DataGrid) on the same view(View2)
2. The changes are not shown in view 1 Unless I Close the the view or application and start it again.

// The INotifyProperty is implemented in ViewModelBase Class

View1

<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"   xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:UC="clr-namespace:HRSimplified.Controls"
x:Class="HRSimplified.MainWindow"
Title="MainWindow" Height="628" Width="986">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="2*" />
        </Grid.ColumnDefinitions>

        <UC:EmployeeGridControl Grid.Column="1" />
    </Grid>
</Window>

View2

<Window
    x:Class="HRSimplified.Windows.EmployeeDashboard"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:Converters="clr-namespace:HRSimplified.Converters"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:local="clr-namespace:HRSimplified.View"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:system="clr-namespace:System;assembly=mscorlib"
    xmlns:VM="clr-namespace:HRSimplified.ViewModel"
    xmlns:UC="clr-namespace:HRSimplified.Controls"
    mc:Ignorable="d"
    Title="EmployeeDashboard">
    <Window.DataContext>
        <VM:ViewModel_Employee />
    </Window.DataContext>
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="2*" />
        </Grid.ColumnDefinitions>
                            <UC:EmployeeGridControl />
                            <ItemsControl ItemsSource="{Binding Path=emp}">
                                <StackPanel>                                   
                                    <TextBox EditValue="{Binding emp.Name, NotifyOnTargetUpdated=True, NotifyOnSourceUpdated=True}" Margin="5" />
<Button Command="{Binding AddCommand, UpdateSourceTrigger=PropertyChanged, NotifyOnTargetUpdated=True, NotifyOnSourceUpdated=True, ValidatesOnDataErrors=True}" Margin="5" Height="35" />
                                 </StackPanel>   
                            </ItemsControl>
</Window>

UserControl

<UserControl 
x:Class="HRSimplified.Controls.EmployeeGridControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:Converters="clr-namespace:HRSimplified.Converters"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
xmlns:local="clr-namespace:HRSimplified.View"
xmlns:system="clr-namespace:System;assembly=mscorlib"
xmlns:VM="clr-namespace:HRSimplified.ViewModel"
mc:Ignorable="d" 
d:DesignHeight="450" 
d:DesignWidth="800">
<Grid>
<DataGrid x:Name="MasterData" MaxHeight="1080" ItemsSource="{Binding MasterData, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, NotifyOnTargetUpdated=True, NotifyOnSourceUpdated=True}">
            <DataGridTextColumn x:Name="Name" Binding="{Binding Mode=TwoWay}" />
                
        </DataGrid>
        
    </Grid>
</UserControl>

ViewModel_Employee

public class ViewModel_Employee:ViewModelBase
    {
        public HRSimplifiedEntities Model = new HRSimplifiedEntities();
        private ObservableCollection<Model.Employee> _MasterData;
        public ObservableCollection<Model.Employee> MasterData
        {
            get
            {
                return _MasterData;
            }
            set
            {
                SetProperty(ref this._MasterData, value);
            }
        }
        private Employee _emp;

        
        private ICommand _submitCommand;
        public Employee emp
        {
            get { return _emp; }
            set
            {
                _emp = value;
                OnPropertyChanged("EmployeeCollection");
            }
        }

        public ViewModel_Employee()
        {
            MasterData = new ObservableCollection<Model.Employee> 
            (Model.Employees.ToList() as IEnumerable<Employee>);
        }
        public ICommand AddCommand
        {
            get
            {
                if (_submitCommand== null)
                {
                    _submitCommand = new RelayCommand(executeMethod, canExecuteMethod, false);
                }
                return _submitCommand;
            }
        }

        private bool canExecuteMethod(object parameter)
        {
            if (string.IsNullOrEmpty(emp.Name) || string.IsNullOrEmpty(emp.Gender) || 
                string.IsNullOrEmpty(emp.Salary.ToString()))
                return false;
            else
                return true;
        }
        private void executeMethod(object parameter)
        {
                MasterData.Add(emp);

                Model.Employees.Add(emp);
                Model.SaveChanges();

                System.Media.SystemSounds.Beep.Play();
        }

What I have tried:

I used the same view model on both views.
but I think it creates a new instance of the view model and datacontext on each view.
I want to resolve this issue.