diff --git a/lmxproxy/src/ZB.MOM.WW.LmxProxy.Host/Grpc/Services/ScadaGrpcService.cs b/lmxproxy/src/ZB.MOM.WW.LmxProxy.Host/Grpc/Services/ScadaGrpcService.cs
index 0f961da..7bf5fe2 100644
--- a/lmxproxy/src/ZB.MOM.WW.LmxProxy.Host/Grpc/Services/ScadaGrpcService.cs
+++ b/lmxproxy/src/ZB.MOM.WW.LmxProxy.Host/Grpc/Services/ScadaGrpcService.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Diagnostics;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 using Grpc.Core;
 using GrpcStatus = Grpc.Core.Status;
@@ -365,12 +366,41 @@ namespace ZB.MOM.WW.LmxProxy.Host.Grpc.Services
 
             try
             {
-                while (await reader.WaitToReadAsync(context.CancellationToken))
+                // Use a combined approach: check both the gRPC cancellation token AND
+                // periodic session validity. This works around Grpc.Core not reliably
+                // firing CancellationToken on client disconnect.
+                while (true)
                 {
-                    while (reader.TryRead(out var item))
+                    // Wait for data with a timeout so we can periodically check session validity
+                    using (var timeoutCts = new CancellationTokenSource(TimeSpan.FromSeconds(30)))
+                    using (var linkedCts = CancellationTokenSource.CreateLinkedTokenSource(
+                        context.CancellationToken, timeoutCts.Token))
                     {
-                        var protoVtq = ConvertToProtoVtq(item.address, item.vtq);
-                        await responseStream.WriteAsync(protoVtq);
+                        bool hasData;
+                        try
+                        {
+                            hasData = await reader.WaitToReadAsync(linkedCts.Token);
+                        }
+                        catch (OperationCanceledException) when (timeoutCts.IsCancellationRequested
+                                                                  && !context.CancellationToken.IsCancellationRequested)
+                        {
+                            // Timeout expired, not a client disconnect — check if session is still valid
+                            if (!_sessionManager.ValidateSession(request.SessionId))
+                            {
+                                Log.Information("Subscribe stream ending — session {SessionId} no longer valid",
+                                    request.SessionId);
+                                break;
+                            }
+                            continue; // Session still valid, keep waiting
+                        }
+
+                        if (!hasData) break; // Channel completed
+
+                        while (reader.TryRead(out var item))
+                        {
+                            var protoVtq = ConvertToProtoVtq(item.address, item.vtq);
+                            await responseStream.WriteAsync(protoVtq);
+                        }
                     }
                 }
             }
diff --git a/lmxproxy/src/ZB.MOM.WW.LmxProxy.Host/LmxProxyService.cs b/lmxproxy/src/ZB.MOM.WW.LmxProxy.Host/LmxProxyService.cs
index 2e5beed..dd8cf43 100644
--- a/lmxproxy/src/ZB.MOM.WW.LmxProxy.Host/LmxProxyService.cs
+++ b/lmxproxy/src/ZB.MOM.WW.LmxProxy.Host/LmxProxyService.cs
@@ -112,6 +112,11 @@ namespace ZB.MOM.WW.LmxProxy.Host
 
                 // 8. Create SessionManager
                 _sessionManager = new SessionManager(inactivityTimeoutMinutes: 5);
+                _sessionManager.OnSessionScavenged(sessionId =>
+                {
+                    Log.Information("Cleaning up subscriptions for scavenged session {SessionId}", sessionId);
+                    _subscriptionManager.UnsubscribeClient(sessionId);
+                });
 
                 // 9. Create performance metrics
                 _performanceMetrics = new PerformanceMetrics();
diff --git a/lmxproxy/src/ZB.MOM.WW.LmxProxy.Host/Sessions/SessionManager.cs b/lmxproxy/src/ZB.MOM.WW.LmxProxy.Host/Sessions/SessionManager.cs
index c0ef555..4e80b7c 100644
--- a/lmxproxy/src/ZB.MOM.WW.LmxProxy.Host/Sessions/SessionManager.cs
+++ b/lmxproxy/src/ZB.MOM.WW.LmxProxy.Host/Sessions/SessionManager.cs
@@ -20,6 +20,7 @@ namespace ZB.MOM.WW.LmxProxy.Host.Sessions
 
         private readonly Timer? _scavengingTimer;
         private readonly TimeSpan _inactivityTimeout;
+        private Action<string>? _onSessionScavenged;
 
         /// <summary>
         ///     Creates a SessionManager with optional inactivity scavenging.
@@ -40,6 +41,15 @@ namespace ZB.MOM.WW.LmxProxy.Host.Sessions
             }
         }
 
+        /// <summary>
+        ///     Register a callback invoked when a session is scavenged due to inactivity.
+        ///     The callback receives the session ID.
+        /// </summary>
+        public void OnSessionScavenged(Action<string> callback)
+        {
+            _onSessionScavenged = callback;
+        }
+
         /// <summary>Gets the count of active sessions.</summary>
         public int ActiveSessionCount => _sessions.Count;
 
@@ -113,6 +123,15 @@ namespace ZB.MOM.WW.LmxProxy.Host.Sessions
                 {
                     Log.Information("Session {SessionId} scavenged (inactive since {LastActivity})",
                         kvp.Key, kvp.Value.LastActivity);
+
+                    try
+                    {
+                        _onSessionScavenged?.Invoke(kvp.Key);
+                    }
+                    catch (Exception ex)
+                    {
+                        Log.Warning(ex, "Error in session scavenge callback for {SessionId}", kvp.Key);
+                    }
                 }
             }
         }