diff --git a/FaultRecordWindow.xaml b/FaultRecordWindow.xaml
index 5b0520bef..cbcccec56 100644
--- a/FaultRecordWindow.xaml
+++ b/FaultRecordWindow.xaml
@@ -254,6 +254,24 @@
                           SelectionChanged="FaultRecordsGrid_SelectionChanged">
                     <DataGrid.Columns>
                         <DataGridTemplateColumn Header="Get" Width="48">
+                            <!-- Restrict the zero-inset alignment to this checkbox column.
+                                 Other text headers/cells retain the existing 9px typography inset. -->
+                            <DataGridTemplateColumn.HeaderStyle>
+                                <Style TargetType="{x:Type DataGridColumnHeader}"
+                                       BasedOn="{StaticResource {x:Type DataGridColumnHeader}}">
+                                    <Setter Property="Padding" Value="0"/>
+                                    <Setter Property="HorizontalContentAlignment" Value="Center"/>
+                                    <Setter Property="VerticalContentAlignment" Value="Center"/>
+                                </Style>
+                            </DataGridTemplateColumn.HeaderStyle>
+                            <DataGridTemplateColumn.CellStyle>
+                                <Style TargetType="{x:Type DataGridCell}"
+                                       BasedOn="{StaticResource {x:Type DataGridCell}}">
+                                    <Setter Property="Padding" Value="0"/>
+                                    <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
+                                    <Setter Property="VerticalContentAlignment" Value="Center"/>
+                                </Style>
+                            </DataGridTemplateColumn.CellStyle>
                             <DataGridTemplateColumn.CellTemplate>
                                 <DataTemplate>
                                     <CheckBox IsChecked="{Binding IsSelected, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
diff --git a/IpConnectWizardWindow.xaml b/IpConnectWizardWindow.xaml
index 486907ea8..44e76c3e6 100644
--- a/IpConnectWizardWindow.xaml
+++ b/IpConnectWizardWindow.xaml
@@ -50,6 +50,8 @@
                                   Background="{StaticResource TaskDialogCard}"
                                   BorderBrush="{StaticResource TaskDialogBorder}"
                                   IsEditable="True" IsTextSearchEnabled="False"
+                                  HorizontalContentAlignment="Center" VerticalContentAlignment="Center"
+                                  Loaded="RelayIpBox_Loaded"
                                   ToolTip="Enter a new IP address or choose a previously saved address"
                                   ItemsSource="{Binding RecentRelayIps, RelativeSource={RelativeSource AncestorType=Window}}"
                                   Text="{Binding RelayIpAddress, RelativeSource={RelativeSource AncestorType=Window}, UpdateSourceTrigger=LostFocus}"/>
diff --git a/IpConnectWizardWindow.xaml.cs b/IpConnectWizardWindow.xaml.cs
index e0906f574..01728720b 100644
--- a/IpConnectWizardWindow.xaml.cs
+++ b/IpConnectWizardWindow.xaml.cs
@@ -1,6 +1,7 @@
 using System.Collections.ObjectModel;
 using System.Globalization;
 using System.Windows;
+using System.Windows.Controls;
 using ArIED61850Tester.Services;
 
 namespace ArIED61850Tester;
@@ -38,6 +39,19 @@ public IpConnectWizardWindow(string initialIp = "", int initialPort = 102)
         Loaded += (_, _) => RelayIpBox.Focus();
     }
 
+    // WPF's editable ComboBox displays text in a templated TextBox, not directly
+    // in its selection presenter. Apply alignment to both modes while preserving
+    // the theme template, keyboard editing, focus and recent-address binding.
+    private void RelayIpBox_Loaded(object sender, RoutedEventArgs e)
+    {
+        if (RelayIpBox.Template.FindName("PART_EditableTextBox", RelayIpBox) is TextBox editor)
+        {
+            editor.TextAlignment = TextAlignment.Center;
+            editor.HorizontalContentAlignment = HorizontalAlignment.Center;
+            editor.VerticalContentAlignment = VerticalAlignment.Center;
+        }
+    }
+
     private void Connect_Click(object sender, RoutedEventArgs e)
     {
         RelayIpAddress = (RelayIpAddress ?? string.Empty).Trim();
diff --git a/tests/ARSAS.Tests/C264FieldAlignmentRegressionTests.cs b/tests/ARSAS.Tests/C264FieldAlignmentRegressionTests.cs
new file mode 100644
index 000000000..acca79728
--- /dev/null
+++ b/tests/ARSAS.Tests/C264FieldAlignmentRegressionTests.cs
@@ -0,0 +1,96 @@
+using System.Xml.Linq;
+
+namespace ARSAS.Tests;
+
+/// <summary>
+/// Field-reported alignment regressions on the native WPF C264 workstation UI.
+/// Assertions inspect scoped style contracts without launching a relay or Npcap.
+/// </summary>
+public sealed class C264FieldAlignmentRegressionTests
+{
+    private static readonly XNamespace Wpf = "http://schemas.microsoft.com/winfx/2006/xaml/presentation";
+
+    [Fact]
+    public void IedIpAddress_CentersEditableText_WithoutReplacingComboBoxTemplate()
+    {
+        var document = XDocument.Load(Find("IpConnectWizardWindow.xaml"));
+        var combo = document.Descendants(Wpf + "ComboBox")
+            .Single(x => (string?)x.Attribute(XName.Get("Name", "http://schemas.microsoft.com/winfx/2006/xaml")) == "RelayIpBox");
+
+        Assert.Equal("True", (string?)combo.Attribute("IsEditable"));
+        Assert.Equal("Center", (string?)combo.Attribute("HorizontalContentAlignment"));
+        Assert.Equal("Center", (string?)combo.Attribute("VerticalContentAlignment"));
+        Assert.Equal("RelayIpBox_Loaded", (string?)combo.Attribute("Loaded"));
+        Assert.Contains("RecentRelayIps", (string?)combo.Attribute("ItemsSource"));
+        Assert.Contains("RelayIpAddress", (string?)combo.Attribute("Text"));
+        Assert.Empty(combo.Elements(Wpf + "ComboBox.Template"));
+
+        var source = File.ReadAllText(Find("IpConnectWizardWindow.xaml.cs"));
+        Assert.Contains("RelayIpBox.Template.FindName(\"PART_EditableTextBox\", RelayIpBox)", source);
+        Assert.Contains("editor.TextAlignment = TextAlignment.Center;", source);
+        Assert.Contains("editor.VerticalContentAlignment = VerticalAlignment.Center;", source);
+        Assert.Contains("UserPreferenceStore.LoadRecentEndpoints()", source);
+        Assert.Contains("System.Net.IPAddress.TryParse", source);
+    }
+
+    [Fact]
+    public void FaultRecordSelectAllAndRows_CenterInSameInsetFreeColumn_WithoutChangingOtherColumns()
+    {
+        var document = XDocument.Load(Find("FaultRecordWindow.xaml"));
+        var checkboxColumn = document.Descendants(Wpf + "DataGridTemplateColumn")
+            .Single(x => (string?)x.Attribute("Header") == "Get");
+
+        Assert.Equal("48", (string?)checkboxColumn.Attribute("Width"));
+        var header = checkboxColumn.Element(Wpf + "DataGridTemplateColumn.HeaderStyle")!
+            .Element(Wpf + "Style")!;
+        var cell = checkboxColumn.Element(Wpf + "DataGridTemplateColumn.CellStyle")!
+            .Element(Wpf + "Style")!;
+        Assert.Equal("{StaticResource {x:Type DataGridColumnHeader}}", (string?)header.Attribute("BasedOn"));
+        Assert.Equal("{StaticResource {x:Type DataGridCell}}", (string?)cell.Attribute("BasedOn"));
+        AssertSetter(header, "Padding", "0");
+        AssertSetter(header, "HorizontalContentAlignment", "Center");
+        AssertSetter(cell, "Padding", "0");
+        AssertSetter(cell, "HorizontalContentAlignment", "Stretch");
+
+        var rowCheckbox = checkboxColumn.Descendants(Wpf + "CheckBox").Single();
+        Assert.Equal("Center", (string?)rowCheckbox.Attribute("HorizontalAlignment"));
+        Assert.Equal("Center", (string?)rowCheckbox.Attribute("VerticalAlignment"));
+        Assert.Contains("IsSelected", (string?)rowCheckbox.Attribute("IsChecked"));
+        Assert.Contains("CanSelectForDownload", (string?)rowCheckbox.Attribute("IsEnabled"));
+
+        // Text and status columns keep the existing 9px global typography inset.
+        Assert.Contains(document.Descendants(Wpf + "Style"),
+            s => (string?)s.Attribute("TargetType") == "DataGridColumnHeader"
+                && s.Elements(Wpf + "Setter").Any(p =>
+                    (string?)p.Attribute("Property") == "Padding" &&
+                    (string?)p.Attribute("Value") == "9,0"));
+        Assert.Contains(document.Descendants(Wpf + "Style"),
+            s => (string?)s.Attribute("TargetType") == "DataGridCell"
+                && s.Elements(Wpf + "Setter").Any(p =>
+                    (string?)p.Attribute("Property") == "Padding" &&
+                    (string?)p.Attribute("Value") == "9,0"));
+
+        var code = File.ReadAllText(Find("FaultRecordWindow.HeaderSelection.cs"));
+        Assert.Contains("IsThreeState = true", code);
+        Assert.Contains("HorizontalAlignment = HorizontalAlignment.Center", code);
+        Assert.Contains("column.Header = headerCheckBox", code);
+        Assert.Contains("FaultRecordHeaderSelectionCheckBox_Click", code);
+    }
+
+    private static void AssertSetter(XElement style, string name, string value)
+        => Assert.Contains(style.Elements(Wpf + "Setter"),
+            setter => (string?)setter.Attribute("Property") == name &&
+                      (string?)setter.Attribute("Value") == value);
+
+    private static string Find(string path)
+    {
+        DirectoryInfo? d = new(AppContext.BaseDirectory);
+        while (d is not null)
+        {
+            var file = Path.Combine(d.FullName, path);
+            if (File.Exists(file)) return file;
+            d = d.Parent;
+        }
+        throw new FileNotFoundException(path);
+    }
+}