diff --git a/src/libraries/Microsoft.Extensions.Caching.Memory/tests/AssemblyAttributes.cs b/src/libraries/Microsoft.Extensions.Caching.Memory/tests/AssemblyAttributes.cs
index 167b80352f5296c009e5acc5d4e0250a12bbf535..2a244c823cc48e9f9bb0afb63208a2f40d7bcc76 100644
--- a/src/libraries/Microsoft.Extensions.Caching.Memory/tests/AssemblyAttributes.cs
+++ b/src/libraries/Microsoft.Extensions.Caching.Memory/tests/AssemblyAttributes.cs
@@ -3,4 +3,4 @@
 
 using Xunit;
 
-[assembly: ActiveIssue("https://github.com/dotnet/runtime/issues/35970", TestRuntimes.Mono)]
+[assembly: ActiveIssue("https://github.com/dotnet/runtime/issues/35970", TestRuntimes.Mono)] // Note: remove IgnoreForCI from .csproj when reenabling
diff --git a/src/libraries/Microsoft.Extensions.Caching.Memory/tests/Microsoft.Extensions.Caching.Memory.Tests.csproj b/src/libraries/Microsoft.Extensions.Caching.Memory/tests/Microsoft.Extensions.Caching.Memory.Tests.csproj
index 429cde4c0db438b8885e3b24a672cd916645dafc..1d602a71c1616b8bb3a71dfe72688ebfd2256d18 100644
--- a/src/libraries/Microsoft.Extensions.Caching.Memory/tests/Microsoft.Extensions.Caching.Memory.Tests.csproj
+++ b/src/libraries/Microsoft.Extensions.Caching.Memory/tests/Microsoft.Extensions.Caching.Memory.Tests.csproj
@@ -3,6 +3,8 @@
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetFrameworkMinimum)</TargetFrameworks>
     <EnableDefaultItems>true</EnableDefaultItems>
+    <!-- ActiveIssue in AssemblyInfo.cs for Mono -->
+    <IgnoreForCI Condition="'$(RuntimeFlavor)' == 'Mono'">true</IgnoreForCI>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/libraries/Microsoft.Extensions.Hosting/tests/FunctionalTests/Microsoft.Extensions.Hosting.Functional.Tests.csproj b/src/libraries/Microsoft.Extensions.Hosting/tests/FunctionalTests/Microsoft.Extensions.Hosting.Functional.Tests.csproj
index 11a32baa9ccb61bb755fd96435051a2c513ecba7..83bb46beb4470faf8201f88f1c4ca3589208b34a 100644
--- a/src/libraries/Microsoft.Extensions.Hosting/tests/FunctionalTests/Microsoft.Extensions.Hosting.Functional.Tests.csproj
+++ b/src/libraries/Microsoft.Extensions.Hosting/tests/FunctionalTests/Microsoft.Extensions.Hosting.Functional.Tests.csproj
@@ -3,6 +3,8 @@
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent);$(NetFrameworkMinimum)</TargetFrameworks>
     <EnableDefaultItems>true</EnableDefaultItems>
+    <!-- ActiveIssue in AssemblyInfo.cs -->
+    <IgnoreForCI>true</IgnoreForCI>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/libraries/Microsoft.Extensions.Hosting/tests/FunctionalTests/Properties/AssemblyInfo.cs b/src/libraries/Microsoft.Extensions.Hosting/tests/FunctionalTests/Properties/AssemblyInfo.cs
index cc0c22363d45b2117956e9b9bfe47353573eb498..3e1a24acf756fce523b96592c12acfcfdafa9ec2 100644
--- a/src/libraries/Microsoft.Extensions.Hosting/tests/FunctionalTests/Properties/AssemblyInfo.cs
+++ b/src/libraries/Microsoft.Extensions.Hosting/tests/FunctionalTests/Properties/AssemblyInfo.cs
@@ -4,3 +4,4 @@
 using Xunit;
 
 [assembly: CollectionBehavior(CollectionBehavior.CollectionPerAssembly)]
+[assembly: ActiveIssue("https://github.com/dotnet/runtime/issues/34090")] // Note: remove IgnoreForCI from .csproj when reenabling
diff --git a/src/libraries/Microsoft.Extensions.Hosting/tests/FunctionalTests/ShutdownTests.cs b/src/libraries/Microsoft.Extensions.Hosting/tests/FunctionalTests/ShutdownTests.cs
index 96ebf6399b5b29219466ccbe3de55c86b3ec3c45..e55a29dd0de78b817dfcdeac1465e26241f1806d 100644
--- a/src/libraries/Microsoft.Extensions.Hosting/tests/FunctionalTests/ShutdownTests.cs
+++ b/src/libraries/Microsoft.Extensions.Hosting/tests/FunctionalTests/ShutdownTests.cs
@@ -29,7 +29,6 @@ public ShutdownTests(ITestOutputHelper output)
         }
 
         [Fact]
-        [ActiveIssue("https://github.com/dotnet/runtime/issues/34090")]
         [PlatformSpecific(TestPlatforms.Linux)]
         public async Task ShutdownTestRun()
         {
@@ -37,7 +36,6 @@ public async Task ShutdownTestRun()
         }
 
         [Fact]
-        [ActiveIssue("https://github.com/dotnet/runtime/issues/34090")]
         [PlatformSpecific(TestPlatforms.Linux)]
         public async Task ShutdownTestWaitForShutdown()
         {
diff --git a/src/libraries/System.ComponentModel.Composition/tests/AssemblyInfo.cs b/src/libraries/System.ComponentModel.Composition/tests/AssemblyInfo.cs
index b0523cb1a69e336761f60f05af6f3d0e57bbaa90..243d54910ab0d324de47e468b4d2ea27fb4b79df 100644
--- a/src/libraries/System.ComponentModel.Composition/tests/AssemblyInfo.cs
+++ b/src/libraries/System.ComponentModel.Composition/tests/AssemblyInfo.cs
@@ -3,4 +3,4 @@
 
 using Xunit;
 
-[assembly: ActiveIssue("https://github.com/mono/mono/issues/16417", TestRuntimes.Mono)] // flaky tests
+[assembly: ActiveIssue("https://github.com/mono/mono/issues/16417", TestRuntimes.Mono)] // flaky tests. Note: remove IgnoreForCI from .csproj when reenabling
diff --git a/src/libraries/System.ComponentModel.Composition/tests/System.ComponentModel.Composition.Tests.csproj b/src/libraries/System.ComponentModel.Composition/tests/System.ComponentModel.Composition.Tests.csproj
index a5f48c6102dc781e3dd91cd5fc89ee42c54ddec7..49cb241dddaf387501a39ff7cc8ec120e0081a1a 100644
--- a/src/libraries/System.ComponentModel.Composition/tests/System.ComponentModel.Composition.Tests.csproj
+++ b/src/libraries/System.ComponentModel.Composition/tests/System.ComponentModel.Composition.Tests.csproj
@@ -2,6 +2,8 @@
   <PropertyGroup>
     <IncludeRemoteExecutor>true</IncludeRemoteExecutor>
     <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
+    <!-- ActiveIssue in AssemblyInfo.cs for Mono -->
+    <IgnoreForCI Condition="'$(RuntimeFlavor)' == 'Mono'">true</IgnoreForCI>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="$(CommonTestPath)System\IO\TempDirectory.cs"