Not-really settable property is a cursed concept

src/Avalonia.Controls/Window.cs

@@ -421,10 +421,12 @@ namespace Avalonia.Controls
                 {
                     PlatformImpl.WindowState = value;
                     var oldValue = _windowStateForPropertyNotifications;
-                    _windowStateForPropertyNotifications = PlatformImpl.WindowState;
                     // If the request was refused - trigger a synthetic property change
                     if (PlatformImpl.WindowState != value)
+                    {
+                        _windowStateForPropertyNotifications = PlatformImpl.WindowState;
                         RaisePropertyChanged(WindowStateProperty, oldValue, _windowStateForPropertyNotifications);
+                    }
                 }
             }
         }

src/Windows/Avalonia.Win32/WindowImpl.AppWndProc.cs

@@ -739,7 +739,8 @@ namespace Avalonia.Win32
                             _ => WindowState.Normal,
                         };
 
-                        var stateChanged = windowState != _lastWindowState;
+                        var stateChanged = windowState != _lastWindowState
+                                           || windowState != _effectiveWindowState; 
                         _lastWindowState = windowState;
 
                         if (Resized != null &&

src/Windows/Avalonia.Win32/WindowImpl.cs

@@ -95,7 +95,10 @@ namespace Avalonia.Win32
         private double _scaling = 1;
         private uint _dpi = 96;
         private WindowState _showWindowState;
+        // Window state, set from various places in code
         private WindowState _lastWindowState;
+        // Window state, set exclusively from WM_SIZE handler before triggering the state change event
+        private WindowState? _effectiveWindowState;
         private OleDropTarget? _dropTarget;
         private Size _minSize;
         private Size _maxSize;
@@ -207,8 +210,7 @@ namespace Avalonia.Win32
         public Action<double>? ScalingChanged { get; set; }
 
         public Action<PixelPoint>? PositionChanged { get; set; }
-
-        private WindowState? _effectiveWindowState;
+        
         public Action<WindowState>? WindowStateChanged { get; set; }
 
         public Action? LostFocus { get; set; }