diff --git a/src/Build.UnitTests/TerminalLoggerConfiguration_Tests.cs b/src/Build.UnitTests/TerminalLoggerConfiguration_Tests.cs
index 6266cb6e4c7..fae6fbcbeb6 100644
--- a/src/Build.UnitTests/TerminalLoggerConfiguration_Tests.cs
+++ b/src/Build.UnitTests/TerminalLoggerConfiguration_Tests.cs
@@ -28,10 +28,6 @@ public TerminalLoggerConfiguration_Tests(ITestOutputHelper output)
     {
         _env = TestEnvironment.Create(output);
 
-        // Ignore environment variables that may have been set by the environment where the tests are running.
-        _env.SetEnvironmentVariable("MSBUILDLIVELOGGER", null);
-        _env.SetEnvironmentVariable("MSBUILDTERMINALLOGGER", null);
-
         TransientTestFolder logFolder = _env.CreateFolder(createFolder: true);
         TransientTestFile projectFile = _env.CreateFile(logFolder, "myProj.proj", $"""
             <Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Hello">
diff --git a/src/MSBuild.UnitTests/MSBuildServer_Tests.cs b/src/MSBuild.UnitTests/MSBuildServer_Tests.cs
index 16fbed5a461..2de493e68b9 100644
--- a/src/MSBuild.UnitTests/MSBuildServer_Tests.cs
+++ b/src/MSBuild.UnitTests/MSBuildServer_Tests.cs
@@ -68,7 +68,7 @@ public class MSBuildServer_Tests : IDisposable
         <ProcessIdTask>
             <Output PropertyName=""PID"" TaskParameter=""Pid"" />
         </ProcessIdTask>
-        <Message Text=""Server ID is $(PID)"" Importance=""High"" />
+        <Message Text=""[Work around Github issue #9667 with --interactive]Server ID is $(PID)"" Importance=""High"" />
     </Target>
 </Project>";
         private static string sleepingTaskContentsFormat = @$"
@@ -313,8 +313,8 @@ public void PropertyMSBuildStartupDirectoryOnServer()
         <ProcessIdTask>
             <Output PropertyName=""PID"" TaskParameter=""Pid"" />
         </ProcessIdTask>
-        <Message Text=""Server ID is $(PID)"" Importance=""High"" />
-		<Message Text="":MSBuildStartupDirectory:$(MSBuildStartupDirectory):"" Importance=""high"" />
+        <Message Text=""[Work around Github issue #9667 with --interactive]Server ID is $(PID)"" Importance=""High"" />
+		<Message Text=""[Work around Github issue #9667 with --interactive]:MSBuildStartupDirectory:$(MSBuildStartupDirectory):"" Importance=""high"" />
 	</Target>
 </Project>";
 
diff --git a/src/UnitTests.Shared/TestEnvironment.cs b/src/UnitTests.Shared/TestEnvironment.cs
index 86e85d3cd51..d961178b298 100644
--- a/src/UnitTests.Shared/TestEnvironment.cs
+++ b/src/UnitTests.Shared/TestEnvironment.cs
@@ -53,6 +53,10 @@ public static TestEnvironment Create(ITestOutputHelper output = null, bool ignor
                 env.WithInvariant(new BuildFailureLogInvariant());
             }
 
+            // Clear these two environment variables first in case pre-setting affects the test.
+            env.SetEnvironmentVariable("MSBUILDLIVELOGGER", null);
+            env.SetEnvironmentVariable("MSBUILDTERMINALLOGGER", null);
+
             return env;
         }
 
@@ -83,10 +87,10 @@ private void Cleanup()
             {
                 _disposed = true;
 
-                // Reset test variants
-                foreach (var variant in _variants)
+                // Reset test variants in reverse order to get back to original state.
+                for (int i = _variants.Count - 1; i >= 0; i--)
                 {
-                    variant.Revert();
+                    _variants[i].Revert();
                 }
 
                 // Assert invariants