diff --git a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/EventPump.cs b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/EventPump.cs
index cdb36a264..20a9a4597 100644
--- a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/EventPump.cs
+++ b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/Runtime/EventPump.cs
@@ -2,6 +2,7 @@ using System.Diagnostics.Metrics;
 using System.Threading.Channels;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
+using ZB.MOM.WW.MxGateway.Client;
 using ZB.MOM.WW.MxGateway.Contracts.Proto;
 using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
 
@@ -512,7 +513,12 @@ internal sealed class EventPump : IAsyncDisposable
                 ServerTimestampUtc: DateTime.UtcNow);
         }
 
-        var statusCode = ev.Statuses.Count > 0
+        // A failure status row wins (it names why the read failed); otherwise the item's OPC DA quality grades
+        // the value. The gateway fills Statuses on every data change, so keying on "any statuses present" meant
+        // Quality was never read and an off-scan / Bad / Uncertain attribute with an OK status row was
+        // published Good (#866 review). Every gateway path (live OnDataChange, value-cache replay, session
+        // snapshot) carries Quality.
+        var statusCode = ev.Statuses.Count > 0 && !ev.Statuses[0].IsSuccess()
             ? StatusCodeMap.FromMxStatus(ev.Statuses[0], _logger)
             : StatusCodeMap.FromQualityByte((byte)(ev.Quality & 0xFF), _logger);
 
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Runtime/EventPumpQualityTests.cs b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Runtime/EventPumpQualityTests.cs
new file mode 100644
index 000000000..f11b46396
--- /dev/null
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/Runtime/EventPumpQualityTests.cs
@@ -0,0 +1,84 @@
+using System.Runtime.CompilerServices;
+using System.Threading.Channels;
+using Google.Protobuf.WellKnownTypes;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.MxGateway.Contracts.Proto;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests.Runtime;
+
+/// <summary>
+///     #866 review: the gateway fills <c>Statuses</c> on every data change, and the pump used the status row
+///     whenever one was present, so the item's OPC DA quality was never read. An off-scan / Bad / Uncertain
+///     attribute carrying an OK status row was published Good. A failure status row still wins.
+/// </summary>
+public sealed class EventPumpQualityTests
+{
+    private const int WaitMs = 10_000;
+
+    private static MxStatusProxy Ok => new() { Success = 1, Category = MxStatusCategory.Ok };
+
+    private sealed class ChannelSubscriber : IGalaxySubscriber
+    {
+        private readonly Channel<MxEvent> _events = Channel.CreateUnbounded<MxEvent>();
+
+        public Task<IReadOnlyList<SubscribeResult>> SubscribeBulkAsync(
+            IReadOnlyList<string> fullReferences, int bufferedUpdateIntervalMs, CancellationToken cancellationToken)
+            => Task.FromResult<IReadOnlyList<SubscribeResult>>([]);
+
+        public Task UnsubscribeBulkAsync(IReadOnlyList<int> itemHandles, CancellationToken cancellationToken) => Task.CompletedTask;
+
+        public async IAsyncEnumerable<MxEvent> StreamEventsAsync([EnumeratorCancellation] CancellationToken cancellationToken)
+        {
+            await foreach (var ev in _events.Reader.ReadAllAsync(cancellationToken).ConfigureAwait(false))
+                yield return ev;
+        }
+
+        public ValueTask EmitAsync(int handle, int quality, MxStatusProxy status)
+        {
+            var ev = new MxEvent
+            {
+                Family = MxEventFamily.OnDataChange,
+                ItemHandle = handle,
+                Value = new MxValue { DoubleValue = 1 },
+                Quality = quality,
+                SourceTimestamp = Timestamp.FromDateTime(DateTime.UtcNow),
+            };
+            ev.Statuses.Add(status);
+            return _events.Writer.WriteAsync(ev);
+        }
+    }
+
+    private static async Task<uint> PublishedStatusAsync(int quality, MxStatusProxy status)
+    {
+        var subscriber = new ChannelSubscriber();
+        var registry = new SubscriptionRegistry();
+        registry.Register(1, [new TagBinding("Tank01.Level", 7)]);
+        var delivered = new TaskCompletionSource<DataChangeEventArgs>(TaskCreationOptions.RunContinuationsAsynchronously);
+
+        await using var pump = new EventPump(subscriber, registry, channelCapacity: 4, clientName: "Quality");
+        pump.OnDataChange += (_, e) => delivered.TrySetResult(e);
+        pump.Start();
+
+        await subscriber.EmitAsync(7, quality, status);
+        (await Task.WhenAny(delivered.Task, Task.Delay(WaitMs, TestContext.Current.CancellationToken))).ShouldBe(delivered.Task);
+        return (await delivered.Task).Snapshot.StatusCode;
+    }
+
+    [Theory]
+    [InlineData(192, 0x00000000u)] // Good
+    [InlineData(24,  0x808D0000u)] // Bad OutOfService (off scan)
+    [InlineData(8,   0x808A0000u)] // Bad NotConnected
+    [InlineData(68,  0x40900000u)] // Uncertain LastUsableValue
+    public async Task An_ok_status_row_is_graded_by_the_item_quality(int quality, uint expected)
+        => (await PublishedStatusAsync(quality, Ok)).ShouldBe(expected);
+
+    [Fact]
+    public async Task A_failure_status_row_wins_over_a_good_quality()
+    {
+        var failure = new MxStatusProxy { Success = 0, Category = MxStatusCategory.CommunicationError, Detail = 2 };
+        (await PublishedStatusAsync(192, failure)).ShouldBe(StatusCodeMap.BadCommunicationError);
+    }
+}