diff --git a/docs/AlarmClientDiscovery.md b/docs/AlarmClientDiscovery.md
index 24045cd..74b87e5 100644
--- a/docs/AlarmClientDiscovery.md
+++ b/docs/AlarmClientDiscovery.md
@@ -236,6 +236,39 @@ omits `InitializeConsumer` entirely — that's a bug fix to apply
 even before A.2 lands, since without it the provider chain never
 becomes visible.
 
+## Subscribe-parameter sweep — fifth probe run, 2026-05-01
+
+Even with `InitializeConsumer` + provider visible at status 100,
+no alarm transitions arrived during a 60s window with the user's
+script flipping the test bool every 10s. Tried:
+
+- `qtSummary` and `qtHistory` (the only `eQueryType` values).
+- Priority 1..999 and 0..32767.
+- `eAlarmFilterState.asNone` and `asAlarmActiveNow` for both
+  `FilterMask` and `FilterSpecification`.
+
+`eAlarmFilterState` is single-state-valued (asNone=0,
+asAlarmActiveNow=1, asAlarmAcked=2, asShelved=3), not flag bits.
+None of these knobs surfaced any alarm activity.
+
+User confirmation 2026-05-01: the test bool does have a
+`BoolAlarm` extension on it; in `aaObjectViewer` the
+`$Alarm.InAlarm` sub-attribute flips true/false in lockstep with
+the script's writes. So the alarm extension is **evaluating**
+its condition, just not visibly producing transitions on the
+`aaAlarmManagedClient` consumer stream.
+
+This isolates the unknown to the producer-side path — whether
+the BoolAlarm extension's "publish to alarm manager" knob is on,
+whether the platform is in an alarm area that matches the
+consumer's subscription scope, or whether AVEVA has a separate
+"events" path the BoolAlarm uses by default that this consumer
+doesn't subscribe to. Resolving requires checking the BoolAlarm
+extension's config in System Platform IDE (alarm priority,
+category, "Active"/"Enabled" flags, alarm-vs-event mode) and
+checking whether `aaObjectViewer`'s Active Alarms panel sees the
+alarm fire.
+
 ### Implications for A.2 implementation
 
 The A.2 PR's value is unmeasurable until at least one alarm
diff --git a/src/MxGateway.Worker.Tests/AlarmClientWmProbeTests.cs b/src/MxGateway.Worker.Tests/AlarmClientWmProbeTests.cs
index 39f1b04..d139583 100644
--- a/src/MxGateway.Worker.Tests/AlarmClientWmProbeTests.cs
+++ b/src/MxGateway.Worker.Tests/AlarmClientWmProbeTests.cs
@@ -257,14 +257,38 @@ public sealed class AlarmClientWmProbeTests : IDisposable
 
             LogProviders(client, "after Register");
 
+            // Dump the eQueryType enum so we can see what alternatives exist
+            // beyond qtSummary, in case Summary aggregates and we need a
+            // List/Snapshot mode instead.
+            try
+            {
+                Type qt = typeof(eQueryType);
+                Log($"eQueryType enum values: " +
+                    string.Join(", ", Enum.GetNames(qt).Select(n =>
+                        $"{n}=0x{Convert.ToInt32(Enum.Parse(qt, n)):X}")));
+                Type af = typeof(eAlarmFilterState);
+                Log($"eAlarmFilterState enum values: " +
+                    string.Join(", ", Enum.GetNames(af).Select(n =>
+                        $"{n}=0x{Convert.ToInt32(Enum.Parse(af, n)):X}")));
+            }
+            catch (Exception ex)
+            {
+                Log($"Enum dump threw: {ex.Message}");
+            }
+
+            // qtHistory + state=ActiveNow: stream historical alarm transitions
+            // including active alarms. asNone for FilterMask/Spec might
+            // literally mean "match alarms in state 'none'" (i.e., nothing),
+            // since the eAlarmFilterState enum is 0/1/2/3 single-states not
+            // flag bits. Try ActiveNow explicitly.
             int subscribe = client.Subscribe(
                 szSubscription: SubscriptionExpression,
-                wFromPri: 1, wToPri: 999,
-                QueryType: eQueryType.qtSummary,
+                wFromPri: 0, wToPri: short.MaxValue,
+                QueryType: eQueryType.qtHistory,
                 SortFlags: eSortFlags.sfReturnNewestFirst,
-                FilterMask: eAlarmFilterState.asNone,
-                FilterSpecification: eAlarmFilterState.asNone);
-            Log($"Subscribe('{SubscriptionExpression}') -> {subscribe}");
+                FilterMask: eAlarmFilterState.asAlarmActiveNow,
+                FilterSpecification: eAlarmFilterState.asAlarmActiveNow);
+            Log($"Subscribe('{SubscriptionExpression}', qtHistory, state=ActiveNow, pri=[0..32767]) -> {subscribe}");
 
             LogProviders(client, "after Subscribe");