diff --git a/src/Nexus.UI/Charts/Chart.razor.cs b/src/Nexus.UI/Charts/Chart.razor.cs
index d9e63437..306f9c7b 100644
--- a/src/Nexus.UI/Charts/Chart.razor.cs
+++ b/src/Nexus.UI/Charts/Chart.razor.cs
@@ -28,6 +28,8 @@ public partial class Chart : IDisposable
     private DateTime _zoomedBegin;
     private DateTime _zoomedEnd;
 
+    private readonly SKRect _defaultZoomBox = new SKRect(0, 0, 1, 1);
+
     /* Common */
     private const float TICK_SIZE = 10;
 
@@ -50,7 +52,6 @@ public partial class Chart : IDisposable
     private readonly TimeAxisConfig[] _timeAxisConfigs;
 
     /* Others */
-    private bool _beginAtZero;
     private readonly SKColor[] _colors;
 
     public Chart()
@@ -133,9 +134,8 @@ public Chart()
 
     protected override void OnParametersSet()
     {
-        if (BeginAtZero != _beginAtZero)
+        if (BeginAtZero || _zoomBox == _defaultZoomBox)
         {
-            _beginAtZero = BeginAtZero;
             Task.Run(() =>
             {
                 _axesMap = LineSeriesData.Series
@@ -523,8 +523,8 @@ private void ApplyZoom(SKRect zoomBox)
     private void ResetZoom()
     {
         /* zoom box */
-        _oldZoomBox = new SKRect(0, 0, 1, 1);
-        _zoomBox = new SKRect(0, 0, 1, 1);
+        _oldZoomBox = _defaultZoomBox;
+        _zoomBox = _defaultZoomBox;
 
         /* time range */
         _zoomedBegin = LineSeriesData.Begin;