diff --git a/docs/ISSUES.md b/docs/ISSUES.md
index d60bfa77..c312a54e 100644
--- a/docs/ISSUES.md
+++ b/docs/ISSUES.md
@@ -1750,11 +1750,25 @@ session; the live gate covered the behavior.
 
 ## #351 — LandblockBuildOriginTests.FarLoad_StripsEnvCellsAndPhysics flake (Debug, load-sensitive)
 
-**Status:** OPEN (filed 2026-08-08). Seen three times today in Debug runs
-under parallel-agent load (5.4 implementer, Slice 6 corrections, dropdown
-polish), each time proven pre-existing by re-running against the pristine
-base commit; never reproduces in clean-room Release. An async streaming
-timing assumption most likely; deflake when it next blocks a verdict.
+**Status:** CLOSED 2026-08-09 (`c6bc2bf7`). NOT a flake and NOT timing —
+the "load-sensitive" framing was wrong: it failed deterministically on
+EVERY Debug `dotnet test` run since the test landed (`090b0354`
+introduced the test and the tripwire in the same commit; the
+parallel-agent-load correlation was just that Debug runs are rare — the
+gate config is Release). Mechanism: the test feeds a far-tier factory
+returning Near payload on purpose to prove the strip safety net, but
+`LandblockStreamer.HandleJob` is documented "fail loud in Debug builds
+and strip in Release" — its `Debug.Assert` fires on exactly that input,
+the VSTest host translates the assert into a thrown
+`DebugAssertException` (its message says so verbatim) instead of killing
+the testhost, and the worker catch folds it into a `Failed` completion,
+so `Assert.IsType<Loaded>` fails. Release compiles the assert out
+(`[Conditional("DEBUG")]`) and strips — hence "never reproduces in
+clean-room Release". Fix: the test now pins BOTH halves of the
+config-divergent contract via `#if DEBUG` (Debug expects the loud
+`Failed` carrying the assert text; Release keeps the strip assertions).
+Production code unchanged; LandblockBuildOriginTests 11/11 in both
+configs.
 
 ## #350 — Render-shadow ledger overflow after 2h42m: lifetime int counters in a never-reset accumulator
 
diff --git a/tests/AcDream.App.Tests/Streaming/LandblockBuildOriginTests.cs b/tests/AcDream.App.Tests/Streaming/LandblockBuildOriginTests.cs
index 9abb646a..678a5452 100644
--- a/tests/AcDream.App.Tests/Streaming/LandblockBuildOriginTests.cs
+++ b/tests/AcDream.App.Tests/Streaming/LandblockBuildOriginTests.cs
@@ -221,23 +221,23 @@ public sealed class LandblockBuildOriginTests
             origin));
         streamer.Start();
 
-        LandblockStreamResult result = await DrainFirstAsync(streamer);
-
 #if DEBUG
-        // LandblockStreamer.HandleJob's near-payload check is "fail loud in
-        // Debug builds and strip in Release" (its own comment): the
-        // Debug.Assert fires on this deliberately-buggy factory, the test
-        // host's trace listener turns it into an exception, and the job's
-        // catch-all publishes it as Failed. That IS the designed Debug
-        // outcome — this test previously asserted the Release strip
-        // unconditionally and so failed on every full Debug run
-        // (found 2026-08-13; the campaign gates all run Release).
-        var failed = Assert.IsType<LandblockStreamResult.Failed>(result);
-        Assert.Equal(landblockId, failed.LandblockId);
+        // The near-payload tripwire is config-divergent by design ("fail loud
+        // in Debug builds and strip in Release" — LandblockStreamer.HandleJob):
+        // in Debug the Debug.Assert fires and the VSTest host translates it
+        // into a thrown DebugAssertException, which the worker's catch folds
+        // into a Failed completion (#351).
+        var failed = Assert.IsType<LandblockStreamResult.Failed>(
+            await DrainFirstAsync(streamer));
+
+        Assert.Contains(
+            "Far-tier factory returned Near payload",
+            failed.Error,
+            StringComparison.Ordinal);
         Assert.Equal(84ul, failed.Generation);
-        Assert.Contains("Far-tier factory returned Near payload", failed.Error);
 #else
-        var loaded = Assert.IsType<LandblockStreamResult.Loaded>(result);
+        var loaded = Assert.IsType<LandblockStreamResult.Loaded>(
+            await DrainFirstAsync(streamer));
 
         Assert.Equal(LandblockStreamTier.Far, loaded.Tier);
         Assert.Empty(loaded.Landblock.Entities);