As a response to Guy Gardener's reflection on the actor...Unfortunately the actor had some sort of stroke that has reduced him to a semi-non-responsive state this past May.
There is an Alexander Enberg page on tumbr somewhere that says he spoke his first word. I think the main reason we haven't seen anymore of the actor is because...well, he's no longer able to. That's too sad, this man's too cute to be catatonic. I don't have all the details b/c his internet bios are sparse.