It looks like you are using an OpenEntityManagerInViewFilter. I am not a big fan of this filter and usually recommend against its use, if you have lazy load exceptions handle that by making sure the data is loaded before the transactional method completes if you know you are going to need it. I am fairly certain your problem stems from the use of that filter, I don't think it can be safely taken across thread boundaries. Try removing it. I don't see anything else amiss in what you have posted.
I am curious sometime to look at the source and see how they handle the multi threading, as entity managers are not thread safe, and the class appears to me to attach the entity manager to a thread local which it keeps for the duration of the request.
It looks like it should be able to handle this, since it has a shouldNotFilterAsyncDispatch() method, but its still the first thing I would take out to see if it helps, since nothing else stands out to me in your code.
Is markUpPCT a transient object (brand new, never been persisted)? I see you are calling entityManager.persist() which assumes the object is new. It would throw an exception if it was not but if there were an exception you wont see it in the code I am looking at. It might also be a good idea to catch any exceptions and log them, inside the async since you cant throw exceptions out of there.