diff --git a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/GalaxyDriver.cs b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/GalaxyDriver.cs
index 2cfc682e4..e548a138a 100644
--- a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/GalaxyDriver.cs
+++ b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/GalaxyDriver.cs
@@ -2162,12 +2162,16 @@ public sealed class GalaxyDriver
                     "GalaxyDriver runtime is shutting down — no subscription can be served until the next InitializeAsync.");
             }
             if (_eventPump is not null) return _eventPump;
-            _eventPump = new EventPump(
+            // The fault callback carries the pump's identity, so a late fault from a pump that is no
+            // longer the live one (a stale pump of a reopened session) is not escalated (#865 review).
+            EventPump? created = null;
+            created = new EventPump(
                 _subscriber!, _subscriptions, _logger,
                 channelCapacity: _options.MxAccess.EventPumpChannelCapacity,
                 clientName: _options.MxAccess.ClientName,
-                onStreamFault: OnEventPumpStreamFault,
+                onStreamFault: cause => OnEventPumpStreamFault(created, cause),
                 onReplayGap: OnEventPumpReplayGap);
+            _eventPump = created;
             _eventPump.OnDataChange += OnPumpDataChange;
             _eventPump.Start();
             return _eventPump;
@@ -2441,7 +2445,7 @@ public sealed class GalaxyDriver
     ///     replay; without this hand-off a transient transport drop permanently kills
     ///     the event stream and <c>GetHealth()</c> keeps reporting Healthy.
     /// </summary>
-    private void OnEventPumpStreamFault(Exception cause)
+    private void OnEventPumpStreamFault(EventPump? source, Exception cause)
     {
         if (_runtimeStopping)
         {
@@ -2451,6 +2455,20 @@ public sealed class GalaxyDriver
             return;
         }
 
+        if (source is not null)
+        {
+            bool stale;
+            lock (_pumpLock) stale = !ReferenceEquals(_eventPump, source) || source.Session != _subscriptions.CurrentSession;
+            if (stale)
+            {
+                // A pump that is no longer the live one (its session was reopened; the replay replaces or
+                // already replaced it). Its fault says nothing about the current transport — and reported
+                // while Replaying it would fail a good replay (#865 review).
+                _logger.LogDebug(cause, "GalaxyDriver {InstanceId} ignored a stream fault from a superseded event pump.", _driverInstanceId);
+                return;
+            }
+        }
+
         var supervisor = _supervisor;
         if (supervisor is null)
         {
diff --git a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/ReconnectSupervisor.cs b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/ReconnectSupervisor.cs
index 43ab2d920..d6ca1318f 100644
--- a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/ReconnectSupervisor.cs
+++ b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/ReconnectSupervisor.cs
@@ -271,9 +271,11 @@ public sealed class ReconnectSupervisor : IDisposable
 
             // === Done — unless the transport failed again while the replay ran ===
             bool faultedDuringReplay;
+            string? replayFault;
             lock (_stateLock)
             {
                 faultedDuringReplay = _faultDuringReplay;
+                replayFault = _lastError;
                 if (!faultedDuringReplay)
                 {
                     _lastError = null;
@@ -285,7 +287,8 @@ public sealed class ReconnectSupervisor : IDisposable
                 // Going Healthy here would hide a dead transport (the fault was swallowed above), and the
                 // next report would restart at attempt 1 with no backoff. Retry this cycle with backoff.
                 _logger.LogWarning(
-                    "Galaxy replay completed but the transport failed again while it ran (attempt {Attempt}) — retrying", attempt);
+                    "Galaxy replay completed but the transport failed again while it ran (attempt {Attempt}: {Fault}) — retrying",
+                    attempt, replayFault);
                 continue;
             }
             _logger.LogInformation("Galaxy reconnect succeeded after {Attempt} attempt(s)", attempt);