If you create and deploy a BPEL process that uses thread.sleep() in a Java Embedding activity, the executing thread is blocked and the transaction associated with that thread is prevented from committing. This causes BPEL instances to appear only after the wait is over, which is the expected behavior.

Instead, use a wait activity, which releases the resource upon entering the activity and enables the ongoing transaction to commit and the BPEL instance data to hydrate into the data store.