Xamarin Forms Bindings not showing on Page - xamarin.forms

Question

I am facing a strange problem and i don't know why this happens. I have created an AccountPage showing the Username, Name and a Description which i bound from the viewmodel. The App checks whether a token exists and pushes a LoginPage if there is no token.
If i now push the create Account Page from the Loginpage and create an account i get popped back to the Account page. Although the OnAppearing Method on the AccountPage gets called and the Bindings have the correct values in the VM there is nothing shown in the view. When i close the app and restart it, however, i can see the values of the Bindings on the View. How does this happen and how can i fix this?
the AccoountPage:
ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:viewmodel="clr-namespace:DoggoApp.ViewModels"
x:DataType="viewmodel:AccountPageViewModel"
BindingContext="AccountPageViewModel"
Title="{Binding Username}"
BackgroundColor="#FBFDFB"
x:Class="DoggoApp.Views.AccountPage">
<ContentPage.Content>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="0.27*"/>
<RowDefinition Height="0.1*"/>
<RowDefinition Height="0.3*"/>
<RowDefinition Height="0.7*"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<StackLayout Orientation="Horizontal" Grid.Row="0">
<Frame CornerRadius="100" Padding="0" Margin="25" IsClippedToBounds="True">
<Image Source="default_user.jpg" Aspect="AspectFill" Scale="0.44" Margin="-60"/>
</Frame>
<StackLayout Margin="10,40">
<Label Text=""/>
<Label Text="Beiträge"
Style="{StaticResource AccountPage}"/>
</StackLayout>
<StackLayout Margin="10,40">
<Label Text=""/>
<Label Text="Follower"
Style="{StaticResource AccountPage}"/>
</StackLayout>
<StackLayout Margin="10,40">
<Label Text=""/>
<Label Text="Following"
Style="{StaticResource AccountPage}"/>
</StackLayout>
</StackLayout>
<StackLayout Grid.Row="1" Margin="15,-20">
<Label Text="{Binding Name}" FontAttributes="Bold" Style="{StaticResource AccountPage}"/>
<Label Text="{Binding Description}" Style="{StaticResource AccountPage}"/>
<Frame Padding="0,15">
<Button Text="Edit Profile" Margin="-20" Clicked="EditAccount_Clicked"/>
</Frame>
</StackLayout>
code behind:
namespace DoggoApp.Views
{
[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class AccountPage : ContentPage
{
private static AccountPageViewModel accountPageViewmodel;
public AccountPage()
{
InitializeComponent();
BindingContext = accountPageViewmodel = new AccountPageViewModel();
}
protected override async void OnAppearing()
{
accountPageViewmodel.NotRefreshTokenAction = (async (obj) =>
{
await DisplayAlert("DoggoApp", "Please log in again", "Ok");
});
base.OnAppearing();
bool LoggedIn = await accountPageViewmodel.Login();
if (!LoggedIn)
{
await Navigation.PushAsync(new LoginPage());
return;
}
}
the viewmodel:
public partial class AccountPageViewModel : ObservableObject, INotifyPropertyChanged
{
// == constants ==
private static readonly IAccountService accountService = DependencyService.Get<IAccountService>();
private static readonly ISaveService saveService = DependencyService.Get<ISaveService>();
// == observable Properties ==
private string username;
[ObservableProperty]
private string name;
[ObservableProperty]
private string description;
public string Username
{
get { return username; }
set
{
username = value;
OnPropertyChanged(nameof(Username));
}
}
public Action<bool> NotRefreshTokenAction { get; set; }
// == Relay Commands ==
[RelayCommand]
public async Task<bool> Login()
{
try
{
bool refreshed = await accountService.RefreshToken();
if(refreshed)
{
AccountDto dto = await accountService.GetDisplayAccount();
Username = dto.username;
Name = dto.name;
Description = dto.description;
return true;
}
throw new Exception("refreshed was false");
}
catch(Exception ex)
{
string message = ex.Message;
Console.WriteLine(message);
return false;
}
}
Create Account VM:
namespace DoggoApp.Views
{
[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class CreateAccountPage : ContentPage
{
private static CreateAccountViewModel createAccountViewModel;
public CreateAccountPage()
{
InitializeComponent();
BindingContext = createAccountViewModel = new CreateAccountViewModel();
createAccountViewModel.AccountCreatedAction = (async (obj) =>
{
await DisplayAlert("Doggoapp", "Registration Successfull", "Ok");
await Navigation.PopToRootAsync();
});
}
}
}