IMHO, there are 2 issues here:

• the fact that the generated query includes 2 parent ids: this is weird
• your exception

If you can reproduce the first issue, that would be very helpful as that would mean we do something really wrong. And I don't think it can be related to Spring.

For the second, you probably need to enable the 2nd level cache in the test case template to try to reproduce it. From what I can see, the NPE means the cache is null.