diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaSdkServer.cs b/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaSdkServer.cs
index 507e9ec3..dff0415c 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaSdkServer.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer/OtOpcUaSdkServer.cs
@@ -271,29 +271,36 @@ public sealed class OtOpcUaSdkServer : StandardServer
         return true;
     }
 
-    // Keep the SDK's full set of calculator factories (live-data AggregateFilter subscriptions need
-    // them, and ServerCapabilities/AggregateFunctions keeps listing all of them), then trim
-    // HistoryServerCapabilities/AggregateFunctions to the node manager's current historian source. At
-    // this point that is the Null default (no history aggregates); the Host's SetHistorianDataSource
-    // re-syncs to the configured backend's set right after start.
+    // Register the same 37 standard aggregate IDs exactly once, using the versioned application
+    // calculators. Calling base first would create the diagnostic nodes twice: SDK 2.0.1's
+    // RegisterFactoryAsync replaces the factory but unconditionally adds another address-space node.
+    // HistoryServerCapabilities is then trimmed to the currently served historian aggregate set.
     /// <inheritdoc />
     protected override async ValueTask<AggregateManager> CreateAggregateManagerAsync(
         IServerInternal server, ApplicationConfiguration configuration, CancellationToken cancellationToken = default)
     {
-        var manager = await base.CreateAggregateManagerAsync(server, configuration, cancellationToken).ConfigureAwait(false);
-        // Pin the SDK manager's default AggregateConfiguration (what live AggregateFilter subscriptions compute under
-        // and what the server advertises) to OUR defaults. Opc.Ua.Server 1.5.378.182 flipped the SDK default of
-        // TreatUncertainAsBad to true; history-read aggregates (Sql.Common evaluators) are fixed at false, so the live
-        // and historical paths must agree and stay behaviour-neutral across the SDK hop (lmxopcua#782).
-        var defaults = manager.GetDefaultConfiguration(NodeId.Null) ?? new AggregateConfiguration();
-        defaults.TreatUncertainAsBad = ServerAggregateConfiguration.TreatUncertainAsBad;
-        defaults.PercentDataBad = ServerAggregateConfiguration.PercentDataBad;
-        defaults.PercentDataGood = ServerAggregateConfiguration.PercentDataGood;
-        defaults.UseSlopedExtrapolation = ServerAggregateConfiguration.UseSlopedExtrapolation;
-        manager.SetDefaultConfiguration(defaults);
-        await Compatibility.Aggregates.CompatibilityAggregateFactory.RegisterAsync(manager, cancellationToken).ConfigureAwait(false);
-        _otOpcUaNodeManager?.SyncAdvertisedAggregates();
-        return manager;
+        var manager = new AggregateManager(server);
+        try
+        {
+            // Pin the SDK manager's default AggregateConfiguration (what live AggregateFilter subscriptions compute under
+            // and what the server advertises) to OUR defaults. Opc.Ua.Server 1.5.378.182 flipped the SDK default of
+            // TreatUncertainAsBad to true; history-read aggregates (Sql.Common evaluators) are fixed at false, so the live
+            // and historical paths must agree and stay behaviour-neutral across the SDK hop (lmxopcua#782).
+            var defaults = manager.GetDefaultConfiguration(NodeId.Null) ?? new AggregateConfiguration();
+            defaults.TreatUncertainAsBad = ServerAggregateConfiguration.TreatUncertainAsBad;
+            defaults.PercentDataBad = ServerAggregateConfiguration.PercentDataBad;
+            defaults.PercentDataGood = ServerAggregateConfiguration.PercentDataGood;
+            defaults.UseSlopedExtrapolation = ServerAggregateConfiguration.UseSlopedExtrapolation;
+            manager.SetDefaultConfiguration(defaults);
+            await Compatibility.Aggregates.CompatibilityAggregateFactory.RegisterAsync(manager, cancellationToken).ConfigureAwait(false);
+            _otOpcUaNodeManager?.SyncAdvertisedAggregates();
+            return manager;
+        }
+        catch
+        {
+            manager.Dispose();
+            throw;
+        }
     }
 
     /// <inheritdoc />