diff --git a/azure-pipelines-official.yml b/azure-pipelines-official.yml
index 982eec0b70..c25160ecc1 100644
--- a/azure-pipelines-official.yml
+++ b/azure-pipelines-official.yml
@@ -75,6 +75,8 @@ extends:
       name: $(DncEngInternalBuildPool)
       image: windows.vs2022preview.amd64
       os: windows
+    settings:
+      networkIsolationPolicy: Permissive,CFSClean
     customBuildTags:
     - ES365AIMigrationTooling
     stages:
diff --git a/test/UnitTests/MSTest.Analyzers.UnitTests/Verifiers/CSharpCodeFixVerifier`2+Test.cs b/test/UnitTests/MSTest.Analyzers.UnitTests/Verifiers/CSharpCodeFixVerifier`2+Test.cs
index 08d678999c..c32383272b 100644
--- a/test/UnitTests/MSTest.Analyzers.UnitTests/Verifiers/CSharpCodeFixVerifier`2+Test.cs
+++ b/test/UnitTests/MSTest.Analyzers.UnitTests/Verifiers/CSharpCodeFixVerifier`2+Test.cs
@@ -19,12 +19,13 @@ public class Test : CSharpCodeFixTest<TAnalyzer, TCodeFix, DefaultVerifier>
     {
         public Test()
         {
+            string nuGetConfigFilePath = Path.Combine(RootFinder.Find(), "NuGet.config");
 #if NET462
-            ReferenceAssemblies = ReferenceAssemblies.NetFramework.Net462.Default;
+            ReferenceAssemblies = ReferenceAssemblies.NetFramework.Net462.WithNuGetConfigFilePath(nuGetConfigFilePath);
             TestState.AdditionalReferences.Add(MetadataReference.CreateFromFile(typeof(ValueTask<>).Assembly.Location));
             TestState.AdditionalReferences.Add(MetadataReference.CreateFromFile(typeof(IAsyncDisposable).Assembly.Location));
 #else
-            ReferenceAssemblies = ReferenceAssemblies.Net.Net80;
+            ReferenceAssemblies = ReferenceAssemblies.Net.Net80.WithNuGetConfigFilePath(nuGetConfigFilePath);
 #endif
             TestState.AdditionalReferences.Add(MetadataReference.CreateFromFile(typeof(ParallelizeAttribute).Assembly.Location));
             TestState.AdditionalReferences.Add(MetadataReference.CreateFromFile(typeof(TestContext).Assembly.Location));
diff --git a/test/UnitTests/MSTest.Analyzers.UnitTests/Verifiers/VisualBasicCodeFixVerifier`2+Test.cs b/test/UnitTests/MSTest.Analyzers.UnitTests/Verifiers/VisualBasicCodeFixVerifier`2+Test.cs
index b308abf39c..1962253b02 100644
--- a/test/UnitTests/MSTest.Analyzers.UnitTests/Verifiers/VisualBasicCodeFixVerifier`2+Test.cs
+++ b/test/UnitTests/MSTest.Analyzers.UnitTests/Verifiers/VisualBasicCodeFixVerifier`2+Test.cs
@@ -19,12 +19,13 @@ public class Test : VisualBasicCodeFixTest<TAnalyzer, TCodeFix, DefaultVerifier>
     {
         public Test()
         {
+            string nuGetConfigFilePath = Path.Combine(RootFinder.Find(), "NuGet.config");
 #if NET462
-            ReferenceAssemblies = ReferenceAssemblies.NetFramework.Net462.Default;
+            ReferenceAssemblies = ReferenceAssemblies.NetFramework.Net462.WithNuGetConfigFilePath(nuGetConfigFilePath);
             TestState.AdditionalReferences.Add(MetadataReference.CreateFromFile(typeof(ValueTask<>).Assembly.Location));
             TestState.AdditionalReferences.Add(MetadataReference.CreateFromFile(typeof(IAsyncDisposable).Assembly.Location));
 #else
-            ReferenceAssemblies = ReferenceAssemblies.Net.Net80;
+            ReferenceAssemblies = ReferenceAssemblies.Net.Net80.WithNuGetConfigFilePath(nuGetConfigFilePath);
 #endif
             TestState.AdditionalReferences.Add(MetadataReference.CreateFromFile(typeof(ParallelizeAttribute).Assembly.Location));
             TestState.AdditionalReferences.Add(MetadataReference.CreateFromFile(typeof(TestContext).Assembly.Location));
diff --git a/test/UnitTests/MSTest.SourceGeneration.UnitTests/TestUtilities/GeneratorTester.cs b/test/UnitTests/MSTest.SourceGeneration.UnitTests/TestUtilities/GeneratorTester.cs
index f67f29e555..87f1705900 100644
--- a/test/UnitTests/MSTest.SourceGeneration.UnitTests/TestUtilities/GeneratorTester.cs
+++ b/test/UnitTests/MSTest.SourceGeneration.UnitTests/TestUtilities/GeneratorTester.cs
@@ -64,8 +64,10 @@ public async Task<GeneratorCompilationResult> CompileAndExecuteAsync(string[] so
             {
                 if (Net80MetadataReferences is null)
                 {
+                    string nuGetConfigFilePath = Path.Combine(RootFinder.Find(), "NuGet.config");
+
                     Net80MetadataReferences =
-                        await ReferenceAssemblies.Net.Net80.ResolveAsync(LanguageNames.CSharp, cancellationToken);
+                        await ReferenceAssemblies.Net.Net80.WithNuGetConfigFilePath(nuGetConfigFilePath).ResolveAsync(LanguageNames.CSharp, cancellationToken);
 
                     GC.Collect();
                     GC.WaitForPendingFinalizers();
diff --git a/test/Utilities/Microsoft.Testing.TestInfrastructure/TestAsset.cs b/test/Utilities/Microsoft.Testing.TestInfrastructure/TestAsset.cs
index 311c105e44..4f9f28a31f 100644
--- a/test/Utilities/Microsoft.Testing.TestInfrastructure/TestAsset.cs
+++ b/test/Utilities/Microsoft.Testing.TestInfrastructure/TestAsset.cs
@@ -109,16 +109,12 @@ public static string GetNuGetConfig(bool addPublicFeeds = false, bool addHashFil
     {
         string publicFeedsFragment = addPublicFeeds
             ? """
-                    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
-                    <add key="test-tools" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/test-tools/nuget/v3/index.json" />
+                <add key="test-tools" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/test-tools/nuget/v3/index.json" />
             """
             : string.Empty;
 
         string publicFeedsMapping = addPublicFeeds
             ? """
-            <packageSource key="nuget.org">
-                <package pattern="*" />
-            </packageSource>
             <packageSource key="test-tools">
                 <package pattern="*" />
             </packageSource>