Wait, is this a new community? I bet you it's a federation issue. If this is the first time that the lemvotes server has been pointed to that community. It may not have a copy of anything on hand to actually check against. Depending on how it works. Piefed and Lemmy both can take a while to populate a new community. And won't do so until the first person from its instance requests to view them. So you might not see much of anything at first but over the next few days especially if there are repeated attempts to access it should try to load in the backlog. But it's not instant. So it may just be a legitimate 404.