diff --git a/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/AlarmCommandRouterTests.cs b/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/AlarmCommandRouterTests.cs
index b629a79f..395cdc04 100644
--- a/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/AlarmCommandRouterTests.cs
+++ b/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/AlarmCommandRouterTests.cs
@@ -354,6 +354,56 @@ public sealed class AlarmCommandRouterTests : IDisposable
         await host.DisposeAsync();
     }
 
+    /// <summary>H6a lifecycle — the native flag is NOT sticky across a rebuild + kind flip. Materialise an
+    /// id as native (flag true), <see cref="OtOpcUaNodeManager.RebuildAddressSpace"/> (which clears the
+    /// folder + condition + native-flag sets), re-ensure the equipment folder, then re-materialise the
+    /// SAME id as scripted (<c>isNative:false</c>). The flag must read false — the rebuild dropped it and
+    /// the scripted re-materialise did NOT re-add it. Guards against a stale-native leak that would route a
+    /// now-scripted alarm's inbound ack to the driver.</summary>
+    [Fact]
+    public async Task Native_flag_clears_on_rebuild_then_kind_flip()
+    {
+        var (host, server) = await BootAsync();
+        var nm = server.NodeManager!;
+
+        nm.EnsureFolder("eq", parentNodeId: null, displayName: "Equipment");
+        nm.MaterialiseAlarmCondition("a1", "eq", "d", "OffNormalAlarm", 700, isNative: true);
+        nm.IsNativeAlarmNode("a1").ShouldBeTrue();
+
+        // RebuildAddressSpace clears the folder set too, so the equipment folder must be re-ensured
+        // before the same id can be re-materialised (ResolveParentFolder needs the parent back).
+        nm.RebuildAddressSpace();
+        nm.EnsureFolder("eq", parentNodeId: null, displayName: "Equipment");
+        nm.MaterialiseAlarmCondition("a1", "eq", "d", "OffNormalAlarm", 700, isNative: false);
+
+        nm.IsNativeAlarmNode("a1").ShouldBeFalse();
+
+        await host.DisposeAsync();
+    }
+
+    /// <summary>H6a lifecycle (converse) — a scripted condition can flip TO native across a rebuild.
+    /// Materialise an id as scripted (flag false), rebuild, re-ensure the folder, re-materialise the SAME
+    /// id as native (<c>isNative:true</c>). The flag must read true — the native re-materialise re-adds it
+    /// cleanly after the rebuild cleared the slate.</summary>
+    [Fact]
+    public async Task Scripted_flag_can_flip_to_native_across_rebuild()
+    {
+        var (host, server) = await BootAsync();
+        var nm = server.NodeManager!;
+
+        nm.EnsureFolder("eq", parentNodeId: null, displayName: "Equipment");
+        nm.MaterialiseAlarmCondition("a1", "eq", "d", "OffNormalAlarm", 700, isNative: false);
+        nm.IsNativeAlarmNode("a1").ShouldBeFalse();
+
+        nm.RebuildAddressSpace();
+        nm.EnsureFolder("eq", parentNodeId: null, displayName: "Equipment");
+        nm.MaterialiseAlarmCondition("a1", "eq", "d", "OffNormalAlarm", 700, isNative: true);
+
+        nm.IsNativeAlarmNode("a1").ShouldBeTrue();
+
+        await host.DisposeAsync();
+    }
+
     /// <summary>Builds a <see cref="ServerSystemContext"/> (an <see cref="ISessionOperationContext"/>)
     /// carrying a <see cref="RoleCarryingUserIdentity"/> with the given name + roles — the exact seam the
     /// gate reads via <c>(context as ISessionOperationContext)?.UserIdentity as RoleCarryingUserIdentity</c>.</summary>
diff --git a/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/Phase7ApplierTests.cs b/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/Phase7ApplierTests.cs
index 074b99d3..42d7a3db 100644
--- a/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/Phase7ApplierTests.cs
+++ b/tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/Phase7ApplierTests.cs
@@ -228,8 +228,9 @@ public sealed class Phase7ApplierTests
         // The alarm tag drove MaterialiseAlarmCondition (folder-scoped NodeId, equipment parent,
         // matching display/type/severity) and did NOT drive EnsureVariable.
         var alarmNodeId = EquipmentNodeIds.Variable("eq-1", "", "OverTemp");
+        // A native equipment-tag alarm: the call-site threads isNative: true.
         sink.AlarmConditionCalls.ShouldHaveSingleItem()
-            .ShouldBe((alarmNodeId, "eq-1", "OverTemp", "OffNormalAlarm", 700));
+            .ShouldBe((alarmNodeId, "eq-1", "OverTemp", "OffNormalAlarm", 700, true));
         sink.VariableCalls.ShouldNotContain(v => v.NodeId == alarmNodeId);
     }
 
@@ -257,8 +258,9 @@ public sealed class Phase7ApplierTests
         sink.FolderCalls.ShouldHaveSingleItem().ShouldBe(("eq-1/Diagnostics", "eq-1", "Diagnostics"));
         // Condition is parented to the sub-folder, with the folder-scoped NodeId. No value variable.
         var alarmNodeId = EquipmentNodeIds.Variable("eq-1", "Diagnostics", "OverTemp");
+        // A native equipment-tag alarm (with a FolderPath): the call-site still threads isNative: true.
         sink.AlarmConditionCalls.ShouldHaveSingleItem()
-            .ShouldBe((alarmNodeId, "eq-1/Diagnostics", "OverTemp", "OffNormalAlarm", 500));
+            .ShouldBe((alarmNodeId, "eq-1/Diagnostics", "OverTemp", "OffNormalAlarm", 500, true));
         sink.VariableCalls.ShouldBeEmpty();
     }
 
@@ -445,8 +447,9 @@ public sealed class Phase7ApplierTests
         applier.MaterialiseScriptedAlarms(composition);
 
         // Only the enabled alarm is materialised; the disabled one is skipped entirely.
+        // A SCRIPTED alarm: the call-site threads isNative: false (guards against a native/scripted swap).
         sink.AlarmConditionCalls.ShouldHaveSingleItem()
-            .ShouldBe(("alm-1", "eq-1", "HighTemp", "OffNormalAlarm", 700));
+            .ShouldBe(("alm-1", "eq-1", "HighTemp", "OffNormalAlarm", 700, false));
     }
 
     /// <summary>Verifies that added equipment tags in an otherwise-empty plan trigger an
@@ -717,7 +720,7 @@ public sealed class Phase7ApplierTests
         /// keyed by NodeId (null ⇒ that call passed not-historized).</summary>
         public ConcurrentQueue<(string NodeId, string? HistorianTagname)> HistorianQueue { get; } = new();
         /// <summary>Gets the queue of alarm-condition materialise calls.</summary>
-        public ConcurrentQueue<(string AlarmNodeId, string EquipmentNodeId, string DisplayName, string AlarmType, int Severity)> AlarmConditionQueue { get; } = new();
+        public ConcurrentQueue<(string AlarmNodeId, string EquipmentNodeId, string DisplayName, string AlarmType, int Severity, bool IsNative)> AlarmConditionQueue { get; } = new();
         /// <summary>Gets the number of rebuild calls made on this sink.</summary>
         public int RebuildCalls;
 
@@ -730,7 +733,7 @@ public sealed class Phase7ApplierTests
         /// <summary>Gets the list of recorded (NodeId, historian-tagname) pairs captured per EnsureVariable call.</summary>
         public List<(string NodeId, string? HistorianTagname)> HistorianCalls => HistorianQueue.ToList();
         /// <summary>Gets the list of recorded alarm-condition materialise calls.</summary>
-        public List<(string AlarmNodeId, string EquipmentNodeId, string DisplayName, string AlarmType, int Severity)> AlarmConditionCalls => AlarmConditionQueue.ToList();
+        public List<(string AlarmNodeId, string EquipmentNodeId, string DisplayName, string AlarmType, int Severity, bool IsNative)> AlarmConditionCalls => AlarmConditionQueue.ToList();
 
         /// <summary>Records a value write (no-op in this recording sink).</summary>
         /// <param name="nodeId">The node ID.</param>
@@ -751,7 +754,7 @@ public sealed class Phase7ApplierTests
         /// <param name="alarmType">The domain alarm type.</param>
         /// <param name="severity">The domain severity.</param>
         public void MaterialiseAlarmCondition(string alarmNodeId, string equipmentNodeId, string displayName, string alarmType, int severity, bool isNative = false)
-            => AlarmConditionQueue.Enqueue((alarmNodeId, equipmentNodeId, displayName, alarmType, severity));
+            => AlarmConditionQueue.Enqueue((alarmNodeId, equipmentNodeId, displayName, alarmType, severity, isNative));
         /// <summary>Records a folder creation call.</summary>
         /// <param name="folderNodeId">The folder node ID.</param>
         /// <param name="parentNodeId">The parent folder node ID, if any.</param>