Apologies, my example above did not include 2nd-level cache annotations. I didn't think they were related to this issue, but after a lot of trial and error, I determined that they are. I've attached an entity class and an EJB. Removing the @Cache annotation from the subcategories field of the entity class also eliminates this issue, but at the cost of not having the collection cached. I tried changing the cache mode to TRANSACTIONAL, but it didn't make a difference.

I am using the same caching strategy on every entity and most collections in my application, and have not seen this issue pop up with other entities, though there could be something unique about this one, or the way I'm updating it in the EJB,