Mocked Entities Persisting with Entity Framework Unit Tests

I have a set of unit tests I run for some Mapper objects that use the .NET Entity Framework, and I think I may have a mocked entity being automatically reused. All tests run fine on their own, but when I run all tests in the solution some tests fail. I found that running certain tests in a certain order would cause failures.

For example, I have a Delete test, a Load test, and an Update test. They all succeed when run separately, but when run in "Delete, Load, Update" order the Update test fails.

After troubleshooting further, I found that the fake entity I create in the Load test is actually being used again in the Update test, even though they are entirely different tests! Here's a code snippet showing how I'm mocking entities:

    using (fakeEntities = Isolate.Fake.Instance<EmeraldsEntitiesContainer>(Members.ReturnRecursiveFakes))
    {
        fakeEntities.ContextOptions.ProxyCreationEnabled = false;
        fakeObjectQuery = Isolate.Fake.Instance<ObjectQuery<Ccsds>>(Members.ReturnRecursiveFakes);
        fakeCcsds = Isolate.Fake.Instance<Ccsds>(Members.MustSpecifyReturnValues);
        Isolate.Swap.NextInstance<EmeraldsEntitiesContainer>().With(fakeEntities);
        Isolate.WhenCalled(() => fakeEntities.CcsdsSet).WillReturn(fakeObjectQuery);
        Isolate.WhenCalled(() => fakeObjectQuery.FirstOrDefault<Ccsds>()).WillReturn(fakeCcsds);

        ...

    }

The fake entity is created nearly the same way in both tests (in the Update test, I use Members.CallOriginal instead of Members.MustSpecifyReturnValues).

I think I may be a victim of some built-in caching the Entity Framework is doing for performance reasons. I've tried adding some fakeEntities.Detach calls and some GC.Collect calls, but haven't had any luck yet. Does anybody know a way to prevent this entity caching? Thanks in advance.

- Dave