Cannot access fields declared in a MappedSuperclass. Javassist proxy generated always returns null for such properties.

A full test case is attached. The test case uses Spring Data JPA to simplify the coding effort but the problem can be reproduced without it as well. Further, the test case contains actual entity classes copied verbatim (including JavaDoc comments) from our production application except for the service layer that has been coded specifically to demonstrate the problem.

You can run the test case easily using Maven.