diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Uns/GlobalUns.razor b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Uns/GlobalUns.razor
index 940e9cba..666bc43a 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Uns/GlobalUns.razor
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Uns/GlobalUns.razor
@@ -127,6 +127,10 @@
     private string? _filter;
     private bool _loading = true;
 
+    // Guards the async modal openers (HandleAddChild/HandleAddVirtualTag/HandleEdit) so a rapid
+    // double-action can't race two service loads into the same modal state.
+    private bool _modalBusy;
+
     // --- Area modal state ---
     private bool _areaModalVisible;
     private bool _areaModalIsNew;
@@ -250,54 +254,72 @@
     /// </summary>
     private async Task HandleAddChild(UnsNode node)
     {
-        CloseModals();
-        switch (node.Kind)
+        if (_modalBusy) { return; }
+        _modalBusy = true;
+        try
         {
-            case UnsNodeKind.Cluster:
-                _areaModalIsNew = true;
-                _areaModalExisting = null;
-                _areaModalClusterId = node.ClusterId ?? node.EntityId;
-                _areaModalVisible = true;
-                break;
+            CloseModals();
+            switch (node.Kind)
+            {
+                case UnsNodeKind.Cluster:
+                    _areaModalIsNew = true;
+                    _areaModalExisting = null;
+                    _areaModalClusterId = node.ClusterId ?? node.EntityId;
+                    _areaModalVisible = true;
+                    break;
 
-            case UnsNodeKind.Area:
-                _lineModalIsNew = true;
-                _lineModalExisting = null;
-                _lineModalAreaId = node.EntityId;
-                _lineModalAreaOptions = AreaOptionsForCluster(node.ClusterId);
-                _lineModalVisible = true;
-                break;
+                case UnsNodeKind.Area:
+                    _lineModalIsNew = true;
+                    _lineModalExisting = null;
+                    _lineModalAreaId = node.EntityId;
+                    _lineModalAreaOptions = AreaOptionsForCluster(node.ClusterId);
+                    _lineModalVisible = true;
+                    break;
 
-            case UnsNodeKind.Line:
-                _equipmentModalIsNew = true;
-                _equipmentModalExisting = null;
-                _equipmentModalLineId = node.EntityId;
-                _equipmentModalLineOptions = LinesForCluster(node.ClusterId);
-                _equipmentModalDriverOptions = await Svc.LoadDriversForClusterAsync(node.ClusterId!);
-                _equipmentModalVisible = true;
-                break;
+                case UnsNodeKind.Line:
+                    _equipmentModalIsNew = true;
+                    _equipmentModalExisting = null;
+                    _equipmentModalLineId = node.EntityId;
+                    _equipmentModalLineOptions = LinesForCluster(node.ClusterId);
+                    _equipmentModalDriverOptions = await Svc.LoadDriversForClusterAsync(node.ClusterId!);
+                    _equipmentModalVisible = true;
+                    break;
 
-            case UnsNodeKind.Equipment:
-                _tagModalIsNew = true;
-                _tagModalExisting = null;
-                _tagModalEquipmentId = node.EntityId;
-                _childRefreshEquipmentId = node.EntityId;
-                _tagModalDriverOptions = await Svc.LoadTagDriversForEquipmentAsync(node.EntityId!);
-                _tagModalVisible = true;
-                break;
+                case UnsNodeKind.Equipment:
+                    _tagModalIsNew = true;
+                    _tagModalExisting = null;
+                    _tagModalEquipmentId = node.EntityId;
+                    _childRefreshEquipmentId = node.EntityId;
+                    _tagModalDriverOptions = await Svc.LoadTagDriversForEquipmentAsync(node.EntityId!);
+                    _tagModalVisible = true;
+                    break;
+            }
+        }
+        finally
+        {
+            _modalBusy = false;
         }
     }
 
     /// <summary>Opens the create modal for a new virtual tag scoped to the clicked equipment.</summary>
     private async Task HandleAddVirtualTag(UnsNode node)
     {
-        CloseModals();
-        _vtagModalIsNew = true;
-        _vtagModalExisting = null;
-        _vtagModalEquipmentId = node.EntityId;
-        _childRefreshEquipmentId = node.EntityId;
-        _vtagModalScriptOptions = await Svc.LoadScriptsAsync();
-        _vtagModalVisible = true;
+        if (_modalBusy) { return; }
+        _modalBusy = true;
+        try
+        {
+            CloseModals();
+            _vtagModalIsNew = true;
+            _vtagModalExisting = null;
+            _vtagModalEquipmentId = node.EntityId;
+            _childRefreshEquipmentId = node.EntityId;
+            _vtagModalScriptOptions = await Svc.LoadScriptsAsync();
+            _vtagModalVisible = true;
+        }
+        finally
+        {
+            _modalBusy = false;
+        }
     }
 
     /// <summary>
@@ -307,60 +329,69 @@
     /// </summary>
     private async Task HandleEdit(UnsNode node)
     {
-        CloseModals();
-        switch (node.Kind)
+        if (_modalBusy) { return; }
+        _modalBusy = true;
+        try
         {
-            case UnsNodeKind.Area:
-                var area = await Svc.LoadAreaAsync(node.EntityId!);
-                if (area is null) { return; }
-                _areaModalIsNew = false;
-                _areaModalExisting = area;
-                _areaModalClusterId = area.ClusterId;
-                _areaModalVisible = true;
-                break;
+            CloseModals();
+            switch (node.Kind)
+            {
+                case UnsNodeKind.Area:
+                    var area = await Svc.LoadAreaAsync(node.EntityId!);
+                    if (area is null) { return; }
+                    _areaModalIsNew = false;
+                    _areaModalExisting = area;
+                    _areaModalClusterId = area.ClusterId;
+                    _areaModalVisible = true;
+                    break;
 
-            case UnsNodeKind.Line:
-                var line = await Svc.LoadLineAsync(node.EntityId!);
-                if (line is null) { return; }
-                _lineModalIsNew = false;
-                _lineModalExisting = line;
-                _lineModalAreaId = line.UnsAreaId;
-                _lineModalAreaOptions = AreaOptionsForCluster(node.ClusterId);
-                _lineModalVisible = true;
-                break;
+                case UnsNodeKind.Line:
+                    var line = await Svc.LoadLineAsync(node.EntityId!);
+                    if (line is null) { return; }
+                    _lineModalIsNew = false;
+                    _lineModalExisting = line;
+                    _lineModalAreaId = line.UnsAreaId;
+                    _lineModalAreaOptions = AreaOptionsForCluster(node.ClusterId);
+                    _lineModalVisible = true;
+                    break;
 
-            case UnsNodeKind.Equipment:
-                var equipment = await Svc.LoadEquipmentAsync(node.EntityId!);
-                if (equipment is null) { return; }
-                _equipmentModalIsNew = false;
-                _equipmentModalExisting = equipment;
-                _equipmentModalLineId = equipment.UnsLineId;
-                _equipmentModalLineOptions = LinesForCluster(node.ClusterId);
-                _equipmentModalDriverOptions = await Svc.LoadDriversForClusterAsync(node.ClusterId!);
-                _equipmentModalVisible = true;
-                break;
+                case UnsNodeKind.Equipment:
+                    var equipment = await Svc.LoadEquipmentAsync(node.EntityId!);
+                    if (equipment is null) { return; }
+                    _equipmentModalIsNew = false;
+                    _equipmentModalExisting = equipment;
+                    _equipmentModalLineId = equipment.UnsLineId;
+                    _equipmentModalLineOptions = LinesForCluster(node.ClusterId);
+                    _equipmentModalDriverOptions = await Svc.LoadDriversForClusterAsync(node.ClusterId!);
+                    _equipmentModalVisible = true;
+                    break;
 
-            case UnsNodeKind.Tag:
-                var tag = await Svc.LoadTagAsync(node.EntityId!);
-                if (tag is null) { return; }
-                _tagModalIsNew = false;
-                _tagModalExisting = tag;
-                _tagModalEquipmentId = tag.EquipmentId;
-                _childRefreshEquipmentId = tag.EquipmentId;
-                _tagModalDriverOptions = await Svc.LoadTagDriversForEquipmentAsync(tag.EquipmentId);
-                _tagModalVisible = true;
-                break;
+                case UnsNodeKind.Tag:
+                    var tag = await Svc.LoadTagAsync(node.EntityId!);
+                    if (tag is null) { return; }
+                    _tagModalIsNew = false;
+                    _tagModalExisting = tag;
+                    _tagModalEquipmentId = tag.EquipmentId;
+                    _childRefreshEquipmentId = tag.EquipmentId;
+                    _tagModalDriverOptions = await Svc.LoadTagDriversForEquipmentAsync(tag.EquipmentId);
+                    _tagModalVisible = true;
+                    break;
 
-            case UnsNodeKind.VirtualTag:
-                var vtag = await Svc.LoadVirtualTagAsync(node.EntityId!);
-                if (vtag is null) { return; }
-                _vtagModalIsNew = false;
-                _vtagModalExisting = vtag;
-                _vtagModalEquipmentId = vtag.EquipmentId;
-                _childRefreshEquipmentId = vtag.EquipmentId;
-                _vtagModalScriptOptions = await Svc.LoadScriptsAsync();
-                _vtagModalVisible = true;
-                break;
+                case UnsNodeKind.VirtualTag:
+                    var vtag = await Svc.LoadVirtualTagAsync(node.EntityId!);
+                    if (vtag is null) { return; }
+                    _vtagModalIsNew = false;
+                    _vtagModalExisting = vtag;
+                    _vtagModalEquipmentId = vtag.EquipmentId;
+                    _childRefreshEquipmentId = vtag.EquipmentId;
+                    _vtagModalScriptOptions = await Svc.LoadScriptsAsync();
+                    _vtagModalVisible = true;
+                    break;
+            }
+        }
+        finally
+        {
+            _modalBusy = false;
         }
     }
 
@@ -505,12 +536,18 @@
     /// <summary>
     /// Reloads a single equipment node's tag/virtual-tag children in place, leaving the rest of the tree
     /// (and the user's expansion) untouched. Falls back to a full structural reload only if the node
-    /// can no longer be found in the current tree.
+    /// can no longer be found in the current tree. Either branch only mutates state — the caller is
+    /// responsible for calling StateHasChanged() afterwards (every current caller does).
     /// </summary>
     private async Task RefreshEquipmentChildrenAsync(string equipmentId)
     {
         var node = FindEquipmentNode(equipmentId);
-        if (node is null) { _roots = await Svc.LoadStructureAsync(); return; }
+        if (node is null)
+        {
+            // Fallback: the equipment node is no longer in the current tree — reload the whole structure.
+            _roots = await Svc.LoadStructureAsync();
+            return;
+        }
 
         var kids = await Svc.LoadEquipmentChildrenAsync(equipmentId);
         node.Children.Clear();
@@ -558,21 +595,29 @@
     private void CloseModals()
     {
         _areaModalVisible = false;
+        _areaModalIsNew = false;
+        _areaModalClusterId = null;
         _areaModalExisting = null;
         _lineModalVisible = false;
+        _lineModalIsNew = false;
+        _lineModalAreaId = null;
         _lineModalExisting = null;
         _lineModalAreaOptions = Array.Empty<(string, string)>();
         _equipmentModalVisible = false;
+        _equipmentModalIsNew = false;
+        _equipmentModalLineId = null;
         _equipmentModalExisting = null;
         _equipmentModalLineOptions = Array.Empty<(string, string)>();
         _equipmentModalDriverOptions = Array.Empty<(string, string)>();
         _tagModalVisible = false;
-        _tagModalExisting = null;
+        _tagModalIsNew = false;
         _tagModalEquipmentId = null;
+        _tagModalExisting = null;
         _tagModalDriverOptions = Array.Empty<(string, string)>();
         _vtagModalVisible = false;
-        _vtagModalExisting = null;
+        _vtagModalIsNew = false;
         _vtagModalEquipmentId = null;
+        _vtagModalExisting = null;
         _vtagModalScriptOptions = Array.Empty<(string, string)>();
         _importModalVisible = false;
         _childRefreshEquipmentId = null;
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/VirtualTagModal.razor b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/VirtualTagModal.razor
index 4b8408b7..a1767c05 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/VirtualTagModal.razor
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/VirtualTagModal.razor
@@ -38,8 +38,12 @@
                         <div class="row">
                             <div class="col-md-6 mb-3">
                                 <label class="form-label" for="vtag-dtype">DataType</label>
-                                <InputText id="vtag-dtype" @bind-Value="_form.DataType" class="form-control form-control-sm mono"
-                                           placeholder="Double" />
+                                <InputSelect id="vtag-dtype" @bind-Value="_form.DataType" class="form-select form-select-sm">
+                                    @foreach (var dt in DataTypes)
+                                    {
+                                        <option value="@dt">@dt</option>
+                                    }
+                                </InputSelect>
                             </div>
                             <div class="col-md-6 mb-3">
                                 <label class="form-label" for="vtag-script">Script</label>
@@ -101,6 +105,11 @@
 }
 
 @code {
+    /// <summary>The OPC UA data types offered for a virtual tag — the same set the TagModal uses.</summary>
+    private static readonly string[] DataTypes =
+        ["Boolean", "SByte", "Byte", "Int16", "UInt16", "Int32", "UInt32",
+         "Int64", "UInt64", "Float", "Double", "String", "DateTime", "Guid", "ByteString"];
+
     /// <summary>Whether the modal is shown. The host owns this flag.</summary>
     [Parameter] public bool Visible { get; set; }