diff --git a/Runtime/Scripts/Controls/ImWindow.cs b/Runtime/Scripts/Controls/ImWindow.cs
index aaf2cc6..740720f 100644
--- a/Runtime/Scripts/Controls/ImWindow.cs
+++ b/Runtime/Scripts/Controls/ImWindow.cs
@@ -29,16 +29,16 @@ public static bool BeginWindow(this ImGui gui, string title, ref bool open, ImSi
         {
             var rect = GetInitialWindowRect(gui, size);
 
-            return BeginWindow(gui, title, ref open, rect, flags);
+            return BeginWindow(gui, title, ref open, ref rect, flags);
         }
 
-        public static void BeginWindow(this ImGui gui, string title, ImRect rect, ImWindowFlag flags = ImWindowFlag.None)
+        public static void BeginWindow(this ImGui gui, string title, ref ImRect rect, ImWindowFlag flags = ImWindowFlag.None)
         {
             var open = true;
-            BeginWindow(gui, title, ref open, rect, flags | ImWindowFlag.NoCloseButton);
+            BeginWindow(gui, title, ref open, ref rect, flags | ImWindowFlag.NoCloseButton);
         }
 
-        public static bool BeginWindow(this ImGui gui, string title, ref bool open, ImRect rect, ImWindowFlag flags = ImWindowFlag.None)
+        public static bool BeginWindow(this ImGui gui, string title, ref bool open, ref ImRect rect, ImWindowFlag flags = ImWindowFlag.None)
         {
             if (!open)
             {
@@ -81,6 +81,8 @@ public static bool BeginWindow(this ImGui gui, string title, ref bool open, ImRe
             gui.Layout.Push(ImAxis.Vertical, contentRect);
             gui.BeginScrollable();
 
+            rect = state.Rect;
+
             return true;
         }
 
diff --git a/Runtime/Scripts/IO/UGUI/ImuiUnityGUIBackend.cs b/Runtime/Scripts/IO/UGUI/ImuiUnityGUIBackend.cs
index 88136ad..df77f27 100644
--- a/Runtime/Scripts/IO/UGUI/ImuiUnityGUIBackend.cs
+++ b/Runtime/Scripts/IO/UGUI/ImuiUnityGUIBackend.cs
@@ -97,7 +97,6 @@ protected override void Awake()
                 }
             }
 
-            scheduler ??= GraphicsSettings.currentRenderPipeline ? new ImuiScriptableRenderingScheduler() : new ImuiBuiltinRenderingScheduler();
             useGUILayout = false;
         }
 
@@ -122,6 +121,8 @@ protected override void OnEnable()
         {
             base.OnEnable();
 
+            scheduler ??= GraphicsSettings.currentRenderPipeline ? new ImuiScriptableRenderingScheduler() : new ImuiBuiltinRenderingScheduler();
+
             if (ClearTexture == null)
             {
                 ClearTexture = new Texture2D(1, 1, TextureFormat.RGBA32, false);