Now, most of my recent comments have at least three downvotes, despite being on different posts and regardless of whether they’re controversial. If you scroll further, all the comments have at least two downvotes, then at least one downvote, and only my oldest comments don’t have this pattern. I’m sure this happened somewhere in the last two hours, because I didn’t see it when I checked it earlier. What happened? Did three people dislike me so much at the same time that they downvoted every comment on my profile that they could scroll to?
Ask the mods in those communities if they will tell you who the downvoters are, then contact the admins of the instance those people are on and explain that you have someone harassing you.
Judging from your post history, I would imagine it’s someone from the Triad down voting you, probably with sockpuppet accounts. There is a portion of fedi that cannot handle Russia or China being anything other than glorified.