[Regression] 10.0.50: Compiled Bindings (TypedBinding) does not resubscribe to intermediary values

[lucastitus]

Description

Release 10.0.50 introduces performance improvements to TypedBindings (#33656), however this introduces a bug where it does not resubscribe to intermediate INPC objects when changed (acc2476#diff-bee8ab0ca9d7b2fdc63c4a340be85c32c8fc33bd437e1e331a93dd84c77d19f3R335)

This was fixed by @StephaneDelcroix on a separate branch, however it did not make it to release
5d6e5a2

Steps to Reproduce

Repro.xaml:

<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:Pages"
             x:Class="Pages.Repro"
             x:DataType="local:Repro" SafeAreaEdges="All">
   <VerticalStackLayout Spacing="10">
       <Label Text="{Binding ViewModel.Text}"/>
       <Button Text="Change View Model" Command="{Binding ChangeViewModelCommand }"/>
       <Button Text="Change Nested" Command="{Binding ChangeNestedCommand }"/>
   </VerticalStackLayout>
</ContentPage>

Repo.xaml.cs:

using System.ComponentModel;
using System.Runtime.CompilerServices;
using CommunityToolkit.Mvvm.Input;

namespace Pages;

public class ReproViewModel : INotifyPropertyChanged
{
    public string Text
    {
        get;
        set 
        {
            field = value;
            OnPropertyChanged();
        }
    }
    
    public event PropertyChangedEventHandler? PropertyChanged;

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

public partial class Repro : ContentPage
{
    public ReproViewModel ViewModel
    {
        get;
        set
        {
            field = value;
            OnPropertyChanged();
        }
    }

    public Repro()
    {
        ViewModel = new ReproViewModel 
        { 
            Text = DateTime.Now.ToString()
        };
        
        BindingContext = this;
        
        InitializeComponent();
    }

    [RelayCommand]
    public void ChangeViewModel()
    {
        ViewModel = new ReproViewModel 
        { 
            Text = DateTime.Now.ToString()
        };
    }
    
    [RelayCommand]
    public void ChangeNested()
    {
        ViewModel.Text = DateTime.Now.ToString();
    }
}

Clicking "Change View Model" then "Change Nested" should still update the label text. This works in versions prior to 10.0.50.

Link to public reproduction project repository

No response

Version with bug

10.0.50

Is this a regression from previous behavior?

Yes, this used to work in .NET MAUI

Last version that worked well

10.0.40

Affected platforms

macOS, iOS, Android, Windows

Affected platform versions

No response

Did you find any workaround?

No response

Relevant log output

[jonathanmourtadahqv]

This is really sad... Have been waiting for the SafeArea fixes that comes with 10.0.50 but now we're hit with this instead and cannot update.

[zwikk]

This is a pretty serious regression. Please do a SR 5.1 soon, I was kinda hoping to finally migrate from net9.0, but the SafeArea bug and now this, prevent us from using net10.0

[NafeelaNazhir]

This issue has been validated in Visual Studio Code 1.111.0 with .NET MAUI versions 10.0.0, 10.0.41, and 10.0.50. The issue is reproducible on Android, iOS, Mac, and Windows platforms in version 10.0.50, but it is not reproduced in versions below 10.0.50.
Note: The issue is reproduced in Release mode, but not in Debug mode.

CompiledBindingIssue.zip

Screen.Recording.2026-03-12.at.4.34.14.PM.mov