diff --git a/NuGet.config b/NuGet.config
index b8e45392bc6..11bcc2d5e56 100644
--- a/NuGet.config
+++ b/NuGet.config
@@ -19,10 +19,6 @@
     <add key="dotnet10-transport" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet10-transport/nuget/v3/index.json" />
     <add key="dotnet-public" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-public/nuget/v3/index.json" />
   </packageSources>
-  <auditSources>
-    <clear />
-    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
-  </auditSources>
   <disabledPackageSources>
     <clear />
     <!--Begin: Package sources managed by Dependency Flow automation. Do not edit the sources below.-->
diff --git a/src/EFCore/ChangeTracking/Internal/ChangeDetector.cs b/src/EFCore/ChangeTracking/Internal/ChangeDetector.cs
index d9d8dea9f5f..042e8744a7d 100644
--- a/src/EFCore/ChangeTracking/Internal/ChangeDetector.cs
+++ b/src/EFCore/ChangeTracking/Internal/ChangeDetector.cs
@@ -283,7 +283,7 @@ private bool LocalDetectChanges(InternalEntryBase entry)
             }
         }
 
-        foreach (var complexProperty in entry.StructuralType.GetComplexProperties())
+        foreach (var complexProperty in entry.StructuralType.GetFlattenedComplexProperties())
         {
             if (complexProperty.IsCollection)
             {
diff --git a/test/EFCore.Tests/ChangeTracking/Internal/InternalComplexEntryTest.cs b/test/EFCore.Tests/ChangeTracking/Internal/InternalComplexEntryTest.cs
index f0089b8d870..ef361b1a753 100644
--- a/test/EFCore.Tests/ChangeTracking/Internal/InternalComplexEntryTest.cs
+++ b/test/EFCore.Tests/ChangeTracking/Internal/InternalComplexEntryTest.cs
@@ -674,6 +674,51 @@ public void GetEntry_throws_when_accessing_invalid_current_ordinal()
         Assert.Equal(CoreStrings.ComplexCollectionEntryOrdinalInvalid(5, "Blog", "Tags", 1), ex.Message);
     }
 
+    [ConditionalFact]
+    public void DetectChanges_detects_changes_in_nested_complex_collections()
+    {
+        var model = CreateModelWithNestedComplexCollections();
+        var entityType = model.FindEntityType(typeof(BlogWithNested))!;
+
+        var serviceProvider = InMemoryTestHelpers.Instance.CreateContextServices(model);
+        var stateManager = serviceProvider.GetRequiredService<IStateManager>();
+        var changeDetector = serviceProvider.GetRequiredService<IChangeDetector>();
+
+        var blog = new BlogWithNested
+        {
+            NestedJson = new NestedJson
+            {
+                Item = new NestedItem { Name = "foo" },
+                Items =
+                [
+                    new NestedItem { Name = "bar" },
+                    new NestedItem { Name = "baz" }
+                ]
+            }
+        };
+
+        var entityEntry = stateManager.GetOrCreateEntry(blog);
+        entityEntry.SetEntityState(EntityState.Unchanged);
+
+        Assert.Equal(EntityState.Unchanged, entityEntry.EntityState);
+
+        // Replace the NestedJson with a new instance that has a modified Items collection
+        blog.NestedJson = blog.NestedJson with
+        {
+            Items =
+            [
+                new NestedItem { Name = "bar" },
+                new NestedItem { Name = "baz" },
+                new NestedItem { Name = "new-bar" }
+            ]
+        };
+
+        // DetectChanges should detect the change in the nested complex collection
+        changeDetector.DetectChanges(stateManager);
+
+        Assert.Equal(EntityState.Modified, entityEntry.EntityState);
+    }
+
     private static IModel CreateModel()
     {
         var modelBuilder = InMemoryTestHelpers.Instance.CreateConventionBuilder();
@@ -688,6 +733,22 @@ private static IModel CreateModel()
         return modelBuilder.FinalizeModel();
     }
 
+    private static IModel CreateModelWithNestedComplexCollections()
+    {
+        var modelBuilder = InMemoryTestHelpers.Instance.CreateConventionBuilder();
+
+        modelBuilder.Entity<BlogWithNested>(eb =>
+        {
+            eb.ComplexProperty(e => e.NestedJson, b =>
+            {
+                b.ComplexProperty(a => a.Item);
+                b.ComplexCollection(a => a.Items);
+            });
+        });
+
+        return modelBuilder.FinalizeModel();
+    }
+
     private class Blog
     {
         public int Id { get; set; }
@@ -714,4 +775,22 @@ private class Category
         public string Name { get; set; } = "";
         public string Description { get; set; } = "";
     }
+
+    private class BlogWithNested
+    {
+        public int Id { get; set; }
+        public string Name { get; set; } = "";
+        public NestedJson NestedJson { get; set; } = new();
+    }
+
+    private record NestedJson
+    {
+        public NestedItem Item { get; init; } = new();
+        public List<NestedItem> Items { get; init; } = [];
+    }
+
+    private record NestedItem
+    {
+        public string Name { get; init; } = "";
+    }
 }