There is problem with passivation of EJB2 stateful bean. Please check my test case:
https://github.com/ochaloup/jboss-as/commit/91459f954225dc2760ae640f912186412160843b

Bean is defined with usage of annotation.
https://github.com/ochaloup/jboss-as/blob/91459f954225dc2760ae640f912186412160843b/testsuite/integration/basic/src/test/java/org/jboss/as/test/integration/ejb/stateful/passivation/ejb2/TestPassivationBean.java

The EJB2 beans are not passivated or ejbPassivate method is not called on passivation event. There could be problem with definition of cache that is used for passivating of EJB2 beans. In case that it should be used another configuration than that for ejb3 beans then this could be only configuration issue.