I'm guessing it's only here on Kbin. For instance I don't see your comment on the non-Kbin side (more>open original url) of this thread (see comment count difference). Then again, federation issues with Kbin is not new either so it is hard to tell (it could just take a day for it to send over). But in this case I'd guess "all actions" does include comments/threads.
Either way I'm not sure there's even a way for you to plainly see that voting is not federated, at least I haven't seen anything like threads from a specific instance that don't have voting arrows or give an error etc.