diff --git a/src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Adapters/RealMxGatewayClient.cs b/src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Adapters/RealMxGatewayClient.cs
index 22b9de16..66f4f1a6 100644
--- a/src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Adapters/RealMxGatewayClient.cs
+++ b/src/ZB.MOM.WW.ScadaBridge.DataConnectionLayer/Adapters/RealMxGatewayClient.cs
@@ -143,7 +143,13 @@ public sealed class RealMxGatewayClient : IMxGatewayClient
         var orderedTags = new List<string>(writes.Count);
         foreach (var (tag, value) in writes)
         {
-            var handle = await GetOrAddItemHandleAsync(tag, ct).ConfigureAwait(false);
+            // MXAccess addresses a WHOLE array attribute with a trailing "[]" on the
+            // item reference. A write to the bare reference is silently dropped — the
+            // COM Write returns success but the value never commits (reads work
+            // either way). This mirrors the AVEVA MES Camstar API, which registers
+            // array tags as "<object>.<attr>[]". Scalars keep the bare reference.
+            var writeRef = IsArrayValue(value) ? tag + "[]" : tag;
+            var handle = await GetOrAddItemHandleAsync(writeRef, ct).ConfigureAwait(false);
             // MXAccess requires a supervisory advise on the item before it will
             // accept a write; without it the worker's synchronous COM Write blocks.
             // With no write-user context we advise supervisory by default (a
@@ -155,13 +161,14 @@ public sealed class RealMxGatewayClient : IMxGatewayClient
             // rejected and the COM write blocks. Pad list values out to the live
             // array's slot count before encoding (callers signal the valid count
             // via a separate scalar, e.g. MoveInNumberWorkOrders).
-            var toWrite = await PadArrayToDeclaredSizeAsync(tag, value, ct).ConfigureAwait(false);
+            var toWrite = await PadArrayToDeclaredSizeAsync(writeRef, value, ct).ConfigureAwait(false);
             entries.Add(new WriteBulkEntry
             {
                 ItemHandle = handle,
                 Value = ToMxValue(toWrite),
                 UserId = _writeUserId,
             });
+            // Map the per-handle result back to the ORIGINAL caller tag (not writeRef).
             orderedTags.Add(tag);
         }
 
@@ -387,6 +394,26 @@ public sealed class RealMxGatewayClient : IMxGatewayClient
         }
     }
 
+    /// <summary>
+    /// Whether a write value is a multi-element (array) attribute value — i.e. one
+    /// <see cref="ToMxValue"/> encodes as an MXAccess array. Such attributes must be
+    /// addressed with a trailing "[]" on the item reference (see <c>WriteAsync</c>).
+    /// The set matches the array cases in <see cref="ToMxValue"/> /
+    /// <see cref="PadArrayToDeclaredSizeAsync"/>; scalars (string, int, bool, …) are false.
+    /// </summary>
+    private static bool IsArrayValue(object? value) => value switch
+    {
+        IReadOnlyList<bool> => true,
+        IReadOnlyList<int> => true,
+        IReadOnlyList<long> => true,
+        IReadOnlyList<float> => true,
+        IReadOnlyList<double> => true,
+        IReadOnlyList<string> => true,
+        IReadOnlyList<DateTimeOffset> => true,
+        IReadOnlyList<DateTime> => true,
+        _ => false,
+    };
+
     private async Task<IReadOnlyList<T>> PadAsync<T>(string tag, IReadOnlyList<T> values, T pad, CancellationToken ct)
     {
         var size = await GetArraySlotCountAsync(tag, ct).ConfigureAwait(false);