Isolate.Verify throws not support objects error on faked obj

The below code throws the following error:

Test method Informedica.GenForm.Library.Tests.UnityTests.IProductServicesTest.Save_product_calls_product_repository_to_save_the_product threw exception:
TypeMock.TypeMockException:
*** Isolate.Verify does not support objects that were not faked using Isolate.Fake.Instance(), or passed through WhenCalled()

If I ommit the [Isolated] attribute I get an index out of bounds error. When I use Isolate.Verify.WasCalledWithArguments, there is no error but the tests passes, should fail thought. So, somehow, Isolate does not spy on the right object.

        [Isolated]
        [TestMethod]
        public void Save_product_calls_product_repository_to_save_the_product()
        {
            var product = LibraryObjectFactory.GetImplementationFor<IProduct>();

            try
            {
                //GetProductServices().SaveProduct(product);
                Isolate.Verify.WasCalledWithExactArguments(() => GetProductRepository(product).SaveProduct(product));
            }
            catch (Exception e)
            {
                if (e.GetType() != typeof(VerifyException)) throw;
                Assert.Fail("product repository was not called to save product");
            }
        }

        private IProductRepository GetProductRepository(IProduct product)
        {
            var repos =  Isolate.Fake.Instance<ProductRepository>();
            Isolate.WhenCalled(() => repos.SaveProduct(product)).IgnoreCall();
            return repos;
        }

However, when I change the code to inline the helper method GetProductRepository, the code runs as expected:

        [Isolated]
        [TestMethod]
        public void Save_product_calls_product_repository_to_save_the_product()
        {
            var product = LibraryObjectFactory.GetImplementationFor<IProduct>();

            try
            {
                //GetProductServices().SaveProduct(product);
                var repos = Isolate.Fake.Instance<ProductRepository>();
                Isolate.WhenCalled(() => repos.SaveProduct(product)).IgnoreCall();
                
                Isolate.Verify.WasCalledWithExactArguments(() => repos.SaveProduct(product));
            }
            catch (Exception e)
            {
                if (e.GetType() != typeof(VerifyException)) throw;
                Assert.Fail("product repository was not called to save product");
            }
        }

        private IProductRepository GetProductRepository(IProduct product)
        {
            var repos =  Isolate.Fake.Instance<ProductRepository>();
            Isolate.WhenCalled(() => repos.SaveProduct(product)).IgnoreCall();
            return repos;
        }