OK, that was a bit of a journey. I have my own single-user instance that I use. All software is buggy. Someone I follow has been boosting notes from Lemmy instances (fine), but my instance fails to parse how Lemmy does votes. So my server's been CPU-pegged for days now, becoming almost unusable. Solution: I've had to block all Lemmy instances to stop parsing of incoming messages about up and down votes. And, now my instance works again. All software is buggy. Always.