diff --git a/docker-dev/seed/seed-clusters.sql b/docker-dev/seed/seed-clusters.sql
index 0b7a1e5..d47d40e 100644
--- a/docker-dev/seed/seed-clusters.sql
+++ b/docker-dev/seed/seed-clusters.sql
@@ -55,45 +55,50 @@ IF NOT EXISTS (SELECT 1 FROM dbo.ServerCluster WHERE ClusterId = 'SITE-B')
 
 ------------------------------------------------------------------------------
 -- ClusterNode — main cluster OPC UA publishers
+--
+-- NodeId is "<compose-service>:4053" so it matches what ClusterRoleInfo +
+-- ConfigPublishCoordinator derive from Akka.Cluster.Get(system).State.Members
+-- (member.Address.Host:Port). NodeDeploymentState.NodeId is FK-bound to
+-- ClusterNode.NodeId; mismatched values cause FK 547 on deploy.
 ------------------------------------------------------------------------------
 
-IF NOT EXISTS (SELECT 1 FROM dbo.ClusterNode WHERE NodeId = 'driver-a')
+IF NOT EXISTS (SELECT 1 FROM dbo.ClusterNode WHERE NodeId = 'driver-a:4053')
     INSERT INTO dbo.ClusterNode
         (NodeId, ClusterId, Host, OpcUaPort, DashboardPort, ApplicationUri, ServiceLevelBase, Enabled, CreatedBy)
-    VALUES ('driver-a', 'MAIN', 'driver-a', 4840, 8081, 'urn:OtOpcUa:driver-a', 200, 1, 'docker-dev-seed');
+    VALUES ('driver-a:4053', 'MAIN', 'driver-a', 4840, 8081, 'urn:OtOpcUa:driver-a', 200, 1, 'docker-dev-seed');
 
-IF NOT EXISTS (SELECT 1 FROM dbo.ClusterNode WHERE NodeId = 'driver-b')
+IF NOT EXISTS (SELECT 1 FROM dbo.ClusterNode WHERE NodeId = 'driver-b:4053')
     INSERT INTO dbo.ClusterNode
         (NodeId, ClusterId, Host, OpcUaPort, DashboardPort, ApplicationUri, ServiceLevelBase, Enabled, CreatedBy)
-    VALUES ('driver-b', 'MAIN', 'driver-b', 4840, 8081, 'urn:OtOpcUa:driver-b', 150, 1, 'docker-dev-seed');
+    VALUES ('driver-b:4053', 'MAIN', 'driver-b', 4840, 8081, 'urn:OtOpcUa:driver-b', 150, 1, 'docker-dev-seed');
 
 ------------------------------------------------------------------------------
 -- ClusterNode — site A
 ------------------------------------------------------------------------------
 
-IF NOT EXISTS (SELECT 1 FROM dbo.ClusterNode WHERE NodeId = 'site-a-1')
+IF NOT EXISTS (SELECT 1 FROM dbo.ClusterNode WHERE NodeId = 'site-a-1:4053')
     INSERT INTO dbo.ClusterNode
         (NodeId, ClusterId, Host, OpcUaPort, DashboardPort, ApplicationUri, ServiceLevelBase, Enabled, CreatedBy)
-    VALUES ('site-a-1', 'SITE-A', 'site-a-1', 4840, 8081, 'urn:OtOpcUa:site-a-1', 200, 1, 'docker-dev-seed');
+    VALUES ('site-a-1:4053', 'SITE-A', 'site-a-1', 4840, 8081, 'urn:OtOpcUa:site-a-1', 200, 1, 'docker-dev-seed');
 
-IF NOT EXISTS (SELECT 1 FROM dbo.ClusterNode WHERE NodeId = 'site-a-2')
+IF NOT EXISTS (SELECT 1 FROM dbo.ClusterNode WHERE NodeId = 'site-a-2:4053')
     INSERT INTO dbo.ClusterNode
         (NodeId, ClusterId, Host, OpcUaPort, DashboardPort, ApplicationUri, ServiceLevelBase, Enabled, CreatedBy)
-    VALUES ('site-a-2', 'SITE-A', 'site-a-2', 4840, 8081, 'urn:OtOpcUa:site-a-2', 150, 1, 'docker-dev-seed');
+    VALUES ('site-a-2:4053', 'SITE-A', 'site-a-2', 4840, 8081, 'urn:OtOpcUa:site-a-2', 150, 1, 'docker-dev-seed');
 
 ------------------------------------------------------------------------------
 -- ClusterNode — site B
 ------------------------------------------------------------------------------
 
-IF NOT EXISTS (SELECT 1 FROM dbo.ClusterNode WHERE NodeId = 'site-b-1')
+IF NOT EXISTS (SELECT 1 FROM dbo.ClusterNode WHERE NodeId = 'site-b-1:4053')
     INSERT INTO dbo.ClusterNode
         (NodeId, ClusterId, Host, OpcUaPort, DashboardPort, ApplicationUri, ServiceLevelBase, Enabled, CreatedBy)
-    VALUES ('site-b-1', 'SITE-B', 'site-b-1', 4840, 8081, 'urn:OtOpcUa:site-b-1', 200, 1, 'docker-dev-seed');
+    VALUES ('site-b-1:4053', 'SITE-B', 'site-b-1', 4840, 8081, 'urn:OtOpcUa:site-b-1', 200, 1, 'docker-dev-seed');
 
-IF NOT EXISTS (SELECT 1 FROM dbo.ClusterNode WHERE NodeId = 'site-b-2')
+IF NOT EXISTS (SELECT 1 FROM dbo.ClusterNode WHERE NodeId = 'site-b-2:4053')
     INSERT INTO dbo.ClusterNode
         (NodeId, ClusterId, Host, OpcUaPort, DashboardPort, ApplicationUri, ServiceLevelBase, Enabled, CreatedBy)
-    VALUES ('site-b-2', 'SITE-B', 'site-b-2', 4840, 8081, 'urn:OtOpcUa:site-b-2', 150, 1, 'docker-dev-seed');
+    VALUES ('site-b-2:4053', 'SITE-B', 'site-b-2', 4840, 8081, 'urn:OtOpcUa:site-b-2', 150, 1, 'docker-dev-seed');
 
 ------------------------------------------------------------------------------
 -- Galaxy MxAccess gateway — MAIN cluster
diff --git a/docker-dev/traefik-dynamic.yml b/docker-dev/traefik-dynamic.yml
index 610d0d8..e54429f 100644
--- a/docker-dev/traefik-dynamic.yml
+++ b/docker-dev/traefik-dynamic.yml
@@ -28,6 +28,14 @@ http:
   services:
     otopcua-admin:
       loadBalancer:
+        # Blazor Server uses SignalR; the WebSocket upgrade must hit the same
+        # backend that owns the circuit ID. Sticky cookie keeps each session
+        # pinned to one node so the post-handshake WebSocket doesn't 404.
+        sticky:
+          cookie:
+            name: otopcua_lb
+            httpOnly: true
+            sameSite: lax
         servers:
           - url: "http://admin-a:9000"
           - url: "http://admin-b:9000"
@@ -38,6 +46,14 @@ http:
 
     otopcua-site-a:
       loadBalancer:
+        # Blazor Server uses SignalR; the WebSocket upgrade must hit the same
+        # backend that owns the circuit ID. Sticky cookie keeps each session
+        # pinned to one node so the post-handshake WebSocket doesn't 404.
+        sticky:
+          cookie:
+            name: otopcua_lb
+            httpOnly: true
+            sameSite: lax
         servers:
           - url: "http://site-a-1:9000"
           - url: "http://site-a-2:9000"
@@ -48,6 +64,14 @@ http:
 
     otopcua-site-b:
       loadBalancer:
+        # Blazor Server uses SignalR; the WebSocket upgrade must hit the same
+        # backend that owns the circuit ID. Sticky cookie keeps each session
+        # pinned to one node so the post-handshake WebSocket doesn't 404.
+        sticky:
+          cookie:
+            name: otopcua_lb
+            httpOnly: true
+            sameSite: lax
         servers:
           - url: "http://site-b-1:9000"
           - url: "http://site-b-2:9000"