Wpf binding not updating with inotifypropertychanged

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C#

XAML

WPF

MVVM

Hello everyone,
I'm new to WPF and MVVM (i use mvvm light) and I'm trying to make an application that has 2 pages. On page 1 is a button that needs to switch the current page to the second page.
When I run my application and i press the button nothing happens. No error no output. So I started debugging and everything works the property changed event gets executed and the right data is passed on.

CODE:
This is the view model for my main window. it has a frame and that frame holds the pages.

using CommonServiceLocator;
using GalaSoft.MvvmLight.Views;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Controls;

namespace WorldCraft.ViewModel
{
    public class MainWindowViewModel : MainViewModel, INotifyPropertyChanged
    {
        public MainWindowViewModel()
        {
           _page = new Pages.Home();
        }

        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }

        private Page page;

        public Page _page
        {
            get
            {
                return page;
            }

            set
            {
                page = value;         
                this.OnPropertyChanged("page");
                
            }
        }
    }
}

this is the xaml for the main page.

<Window x:Class="WorldCraft.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WorldCraft"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800"
        DataContext="{Binding MainWindow, Source={StaticResource Locator}}">
    <Grid>
        <Frame Content="{Binding Path=_page, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
    </Grid>
</Window>

This is the code for the first page called Home. It needs to switch to another page called WorldEditor.

using CommonServiceLocator;
using GalaSoft.MvvmLight;
using GalaSoft.MvvmLight.Command;
using GalaSoft.MvvmLight.Ioc;
using GalaSoft.MvvmLight.Views;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;
using WorldCraft.ViewModel.Commands;

namespace WorldCraft.ViewModel
{
    public class HomeViewModel : MainViewModel
    {

        public NavigateCommand navigateCommand { get; private set; }

        public HomeViewModel()
        {
            navigateCommand = new NavigateCommand(SwitchTest);
            
        }

        public void SwitchTest()
        {
            ServiceLocator.Current.GetInstance<MainWindowViewModel>()._page = new Pages.WorldEditor();

        }

        


    }
}

I don't know what I'm doing wrong. Also, I don't know or this is the right way to navigate between pages. If there is a better way pls let me know.

What I have tried:

searching on the internet but it's hard to describe my problem to google if there is no output of any kind.