diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.ControlPlane/Redundancy/RedundancyStateActor.cs b/src/Server/ZB.MOM.WW.OtOpcUa.ControlPlane/Redundancy/RedundancyStateActor.cs
index 3c276c56..0afcf188 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.ControlPlane/Redundancy/RedundancyStateActor.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.ControlPlane/Redundancy/RedundancyStateActor.cs
@@ -104,7 +104,7 @@ public sealed class RedundancyStateActor : ReceiveActor, IWithTimers
                 : CommonsRedundancyRole.Detached;
 
             list.Add(new NodeRedundancyState(
-                NodeId.Parse(host),
+                ToNodeId(member.Address),
                 role,
                 IsClusterLeader: clusterLeader == member.Address,
                 IsRoleLeaderForDriver: driverLeader == member.Address,
@@ -113,6 +113,16 @@ public sealed class RedundancyStateActor : ReceiveActor, IWithTimers
         return list;
     }
 
+    /// <summary>
+    ///     Builds the canonical cluster node id (<c>host:port</c>) for an Akka member address — the SAME
+    ///     format <c>ClusterRoleInfo.LocalNode</c>/<c>ToNodeId</c> use, so redundancy-state consumers
+    ///     (OPC UA ServiceLevel, scripted-alarm emit gate, historian gate) can match their local node.
+    /// </summary>
+    /// <param name="address">The cluster member's address.</param>
+    /// <returns>The canonical <c>host:port</c> node id.</returns>
+    public static NodeId ToNodeId(Akka.Actor.Address address) =>
+        NodeId.Parse($"{address.Host ?? string.Empty}:{address.Port ?? 0}");
+
     public sealed class RecomputeNow
     {
         public static readonly RecomputeNow Instance = new();
diff --git a/tests/Server/ZB.MOM.WW.OtOpcUa.ControlPlane.Tests/RedundancyStateActorTests.cs b/tests/Server/ZB.MOM.WW.OtOpcUa.ControlPlane.Tests/RedundancyStateActorTests.cs
index 505ada1c..5f0df58e 100644
--- a/tests/Server/ZB.MOM.WW.OtOpcUa.ControlPlane.Tests/RedundancyStateActorTests.cs
+++ b/tests/Server/ZB.MOM.WW.OtOpcUa.ControlPlane.Tests/RedundancyStateActorTests.cs
@@ -42,4 +42,30 @@ public sealed class RedundancyStateActorTests : ControlPlaneActorTestBase
         // After debounce settles, no more events are fired by a quiescent cluster.
         probe.ExpectNoMsg(TimeSpan.FromMilliseconds(500));
     }
+
+    /// <summary>
+    /// Regression guard: the snapshot node id MUST be the canonical <c>host:port</c> form (matching
+    /// ClusterRoleInfo.LocalNode/ToNodeId), or every consumer's
+    /// <c>n.NodeId == _localNode.Value</c> match fails and no node ever learns its role.
+    /// </summary>
+    [Fact]
+    public void ToNodeId_uses_canonical_host_and_port()
+    {
+        var nodeId = RedundancyStateActor.ToNodeId(
+            new Address("akka.tcp", "otopcua", "central-2", 4053));
+
+        nodeId.Value.ShouldBe("central-2:4053");
+    }
+
+    /// <summary>
+    /// Documents the host-less/port-less fallback (<c>:0</c>). Such members are skipped by
+    /// BuildSnapshot's guard, but the helper must still format deterministically.
+    /// </summary>
+    [Fact]
+    public void ToNodeId_handles_missing_port()
+    {
+        var nodeId = RedundancyStateActor.ToNodeId(new Address("akka.tcp", "otopcua"));
+
+        nodeId.Value.ShouldBe(":0");
+    }
 }