diff --git a/src/Platform/Microsoft.Testing.Extensions.GitHubActionsReport/GitHubActionsAnnotationReporter.cs b/src/Platform/Microsoft.Testing.Extensions.GitHubActionsReport/GitHubActionsAnnotationReporter.cs
index 245043adeb..ec19d823b3 100644
--- a/src/Platform/Microsoft.Testing.Extensions.GitHubActionsReport/GitHubActionsAnnotationReporter.cs
+++ b/src/Platform/Microsoft.Testing.Extensions.GitHubActionsReport/GitHubActionsAnnotationReporter.cs
@@ -93,6 +93,9 @@ public async Task ConsumeAsync(IDataProducer dataProducer, IData value, Cancella
                 // workflow Annotations tab alongside failures, rather than being silently absent.
                 if (nodeState is SkippedTestNodeStateProperty skipped)
                 {
+                    // GetTestName is computed lazily at the call sites so the common passing/in-progress path
+                    // (which returns below without annotating) does not walk the property bag or allocate the
+                    // formatted name it would immediately discard.
                     await WriteSkippedAnnotationAsync(GetTestName(nodeUpdateMessage.TestNode), skipped.Explanation, cancellationToken).ConfigureAwait(false);
                 }
 
@@ -114,7 +117,7 @@ public async Task ConsumeAsync(IDataProducer dataProducer, IData value, Cancella
         }
     }
 
-    private async Task WriteAnnotationAsync(string testName, string? explanation, Exception? exception, CancellationToken cancellationToken)
+    private Task WriteAnnotationAsync(string testName, string? explanation, Exception? exception, CancellationToken cancellationToken)
     {
         if (_logger.IsEnabled(LogLevel.Trace))
         {
@@ -129,7 +132,7 @@ private async Task WriteAnnotationAsync(string testName, string? explanation, Ex
             _logger.LogTrace($"Showing failure annotation '{line}'.");
         }
 
-        await DisplayAnnotationLineAsync(line, cancellationToken).ConfigureAwait(false);
+        return DisplayAnnotationLineAsync(line, cancellationToken);
     }
 
     internal static /* for testing */ string GetErrorAnnotation(string testName, string? explanation, Exception? exception, string? repoRoot, IFileSystem fileSystem, ILogger logger, bool skipAssertionFrames)
@@ -158,7 +161,7 @@ private async Task WriteAnnotationAsync(string testName, string? explanation, Ex
             GitHubActionsEscaper.EscapeData(message));
     }
 
-    private async Task WriteSkippedAnnotationAsync(string testName, string? explanation, CancellationToken cancellationToken)
+    private Task WriteSkippedAnnotationAsync(string testName, string? explanation, CancellationToken cancellationToken)
     {
         if (_logger.IsEnabled(LogLevel.Trace))
         {
@@ -172,15 +175,15 @@ private async Task WriteSkippedAnnotationAsync(string testName, string? explanat
             _logger.LogTrace($"Showing skip annotation '{line}'.");
         }
 
-        await DisplayAnnotationLineAsync(line, cancellationToken).ConfigureAwait(false);
+        return DisplayAnnotationLineAsync(line, cancellationToken);
     }
 
-    // Prepend a newline so the workflow command ('::error' or '::warning') always starts at column 0 on its
-    // own line. In CI the terminal output device runs in SimpleAnsi mode and emits a color reset ('\e[m')
-    // WITHOUT a trailing newline after the preceding colored test block. Emitting the annotation directly
-    // would yield "\e[m::error ..." and GitHub only recognizes a workflow command when the line begins with
-    // '::', so the dangling reset would silently drop the annotation. The leading newline pushes the reset
-    // onto its own (ignored) line and keeps the annotation parseable.
+    // Prepend a newline so every workflow command annotation ('::error' or '::warning') starts at column 0
+    // on its own line. In CI the terminal output device runs in SimpleAnsi mode and emits a color reset
+    // ('\e[m') WITHOUT a trailing newline after the preceding colored test block. Emitting the annotation
+    // directly would yield "\e[m::error ..." and GitHub only recognizes a workflow command when the line
+    // begins with '::', so the dangling reset would silently drop the annotation. The leading newline pushes
+    // the reset onto its own (ignored) line and keeps the annotation parseable.
     private Task DisplayAnnotationLineAsync(string line, CancellationToken cancellationToken)
         => _outputDisplay.DisplayAsync(this, new FormattedTextOutputDeviceData($"\n{line}"), cancellationToken);
 
diff --git a/test/UnitTests/Microsoft.Testing.Extensions.UnitTests/GitHubActionsAnnotationReporterTests.cs b/test/UnitTests/Microsoft.Testing.Extensions.UnitTests/GitHubActionsAnnotationReporterTests.cs
index fccbd56e12..32caf6b7d6 100644
--- a/test/UnitTests/Microsoft.Testing.Extensions.UnitTests/GitHubActionsAnnotationReporterTests.cs
+++ b/test/UnitTests/Microsoft.Testing.Extensions.UnitTests/GitHubActionsAnnotationReporterTests.cs
@@ -103,24 +103,21 @@ public void GetSkippedAnnotation_FallsBackToDefaultReason_WhenNoExplanation()
         Assert.AreEqual("::warning title=Test skipped%3A MyNamespace.MyTest::The test was skipped without providing a reason.", text);
     }
 
-    // Throws (and catches) an exception, reporting the exact line of the throw statement so tests can assert the
-    // resolved line without hard-coding a physical number that shifts whenever code above changes.
-    private static Exception CaptureException(string message, out int throwLine)
+    // Produces an exception whose stack trace deterministically points at this test file at a fixed line, so
+    // tests can assert the resolved file and line. A real 'throw' was previously used, but the runtime-reported
+    // line of a thrown exception shifts under Release JIT optimization (observed differing between .NET
+    // Framework net462 and net472), which made the exact-line assertion flaky in CI (see #9658). A synthetic
+    // frame keeps both the resolved file and line stable while still exercising the resolver's real
+    // repo-root/'/_/' path relativization: [CallerFilePath] yields this file's path (mapped to '/_/test/...'
+    // in deterministic CI builds, or an absolute path locally), exactly as a genuine frame would.
+    private static Exception CaptureException(string message, out int throwLine, [CallerFilePath] string filePath = "")
     {
-        throwLine = 0;
-        try
-        {
-            throwLine = CurrentLine() + 1;
-            throw new Exception(message);
-        }
-        catch (Exception ex)
-        {
-            return ex;
-        }
+        throwLine = 12345;
+        return new StackTraceException(
+            $"   at Microsoft.Testing.Extensions.UnitTests.GitHubActionsAnnotationReporterTests.CaptureException() in {filePath}:line {throwLine}",
+            message);
     }
 
-    private static int CurrentLine([CallerLineNumber] int line = 0) => line;
-
     private static IFileSystem CreateFileSystemWhereEveryFileExists()
     {
         var fileSystem = new Mock<IFileSystem>();
@@ -134,7 +131,9 @@ private sealed class StackTraceException : Exception
     {
         private readonly string _stackTrace;
 
-        public StackTraceException(string stackTrace) => _stackTrace = stackTrace;
+        public StackTraceException(string stackTrace, string? message = null)
+            : base(message)
+            => _stackTrace = stackTrace;
 
         public override string? StackTrace => _stackTrace;
     }