1.27.17 breaks AddFallbackServiceProvider

[snerte]

Im registering a AddFallbackServiceProvider. This serviceprovider returns Moqs with AutoMocker for requested services.

        Services.AddFallbackServiceProvider((..));

This works fine in 1.26.64
But when I upgrade to 1.27.17 the tests fail after it suddenly asks my IServiceProvider for IComponentActivator

Here's my stacktrace

Message: 
  System.InvalidOperationException : The component activator returned a null value for a component of type bunit.BlazorTestApp.Components.Routes.

Stack Trace: 
  ComponentFactory.InstantiateComponent(IServiceProvider serviceProvider, Type componentType, IComponentRenderMode callerSpecifiedRenderMode, Nullable`1 parentComponentId)
  Renderer.InstantiateChildComponentOnFrame(RenderTreeFrame[] frames, Int32 frameIndex, Int32 parentComponentId)
  RenderTreeDiffBuilder.InitializeNewComponentFrame(DiffContext& diffContext, Int32 frameIndex)
  RenderTreeDiffBuilder.InitializeNewSubtree(DiffContext& diffContext, Int32 frameIndex)
  RenderTreeDiffBuilder.InsertNewFrame(DiffContext& diffContext, Int32 newFrameIndex)
  RenderTreeDiffBuilder.AppendDiffEntriesForRange(DiffContext& diffContext, Int32 oldStartIndex, Int32 oldEndIndexExcl, Int32 newStartIndex, Int32 newEndIndexExcl)
  RenderTreeDiffBuilder.ComputeDiff(Renderer renderer, RenderBatchBuilder batchBuilder, Int32 componentId, ArrayRange`1 oldTree, ArrayRange`1 newTree)
  ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment, Exception& renderFragmentException)
  Renderer.ProcessRenderQueue()
  --- End of stack trace from previous location ---
  TestRenderer.AssertNoUnhandledExceptions() line 629
  TestRenderer.Render[TResult](RenderFragment renderFragment, Func`2 activator) line 480
  TestRenderer.RenderFragment(RenderFragment renderFragment) line 101
  TestContextBaseRenderExtensions.RenderInsideRenderTree(TestContextBase testContext, RenderFragment renderFragment) line 43
  TestContextBaseRenderExtensions.RenderInsideRenderTree[TComponent](TestContextBase testContext, RenderFragment renderFragment) line 23
  TestContext.Render[TComponent](RenderFragment renderFragment) line 68
  TestContext.RenderComponent[TComponent](Action`1 parameterBuilder) line 54
  AutoMockerTestContextTests.CreatesUnregisteredDependencies() line 14
  RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)
  MethodBaseInvoker.InvokeWithNoArgs(Object obj, BindingFlags invokeAttr)

[linkdotnet]

Hey @snerte,

can you provide us with the component under test and your test setup?