diff --git a/src/libraries/System.Runtime.Extensions/tests/System/AppDomainTests.cs b/src/libraries/System.Runtime.Extensions/tests/System/AppDomainTests.cs
index 2b8160cfa953e2..b6c83de69de1a6 100644
--- a/src/libraries/System.Runtime.Extensions/tests/System/AppDomainTests.cs
+++ b/src/libraries/System.Runtime.Extensions/tests/System/AppDomainTests.cs
@@ -379,7 +379,7 @@ public void ReflectionOnlyGetAssemblies()
         }
 
         [Fact]
-        [SkipOnPlatform(TestPlatforms.Browser, "Throws PNSE")]
+        [SkipOnPlatform(TestPlatforms.Browser | TestPlatforms.iOS | TestPlatforms.tvOS, "Throws PNSE")]
         public void MonitoringIsEnabled()
         {
             Assert.True(AppDomain.MonitoringIsEnabled);
diff --git a/src/libraries/System.Runtime.Extensions/tests/System/EnvironmentTests.cs b/src/libraries/System.Runtime.Extensions/tests/System/EnvironmentTests.cs
index 63723f0117a099..415cafb9f02c25 100644
--- a/src/libraries/System.Runtime.Extensions/tests/System/EnvironmentTests.cs
+++ b/src/libraries/System.Runtime.Extensions/tests/System/EnvironmentTests.cs
@@ -96,6 +96,7 @@ public void ProcessPath_Idempotent()
         }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.tvOS, "Throws PNSE")]
         public void ProcessPath_MatchesExpectedValue()
         {
             string expectedProcessPath = PlatformDetection.IsBrowser ? null : Process.GetCurrentProcess().MainModule.FileName;
diff --git a/src/libraries/tests.proj b/src/libraries/tests.proj
index ddc2ef5d1b610a..6dbb311329b342 100644
--- a/src/libraries/tests.proj
+++ b/src/libraries/tests.proj
@@ -166,7 +166,6 @@
     <ProjectExclusions Include="$(RepoRoot)\src\tests\FunctionalTests\Android\Device_Emulator\AOT\Android.Device_Emulator.Aot.Test.csproj" />
   </ItemGroup>
 
-  <!-- Excluding all tests for devices until building on helix works properly -->
   <ItemGroup Condition="'$(TargetOS)' == 'iOS' and '$(RunDisablediOSTests)' != 'true'">
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)*\tests\**\*.Tests.csproj" />
     
@@ -177,6 +176,11 @@
     <ProjectExclusions Include="$(RepoRoot)\src\tests\FunctionalTests\$(TargetOS)\Device\**\*.Test.csproj" />
   </ItemGroup>
 
+  <ItemGroup Condition="'$(TargetOS)' == 'iOSSimulator' and '$(TargetArchitecture)' == 'arm64' and '$(RunDisablediOSTests)' != 'true'">
+    <!-- Functional tests on arm64 simulator have problems with return codes from mlaunch -->
+    <ProjectExclusions Include="$(RepoRoot)\src\tests\FunctionalTests\$(TargetOS)\Simulator\**\*.Test.csproj" />
+  </ItemGroup>
+
   <!-- Excluding all tests for devices until building on helix works properly -->
   <ItemGroup Condition="'$(TargetOS)' == 'tvOS' and '$(RunDisablediOSTests)' != 'true'">
     <!-- Ref.Emit in XSLCompiledTransform -->