I would guess it’s a federation issue maybe? maybe if a down vote doesn’t federate for whatever reason but the user decided to un-down vote and that does federate? I dunno, just a guess.

It could be vote fuzzing, which is an anti-vote manipulation technique that Reddit uses. It’s largely transparent to the user except for the presence of extra downvotes and net votes that fluctuate

Edit: Okay, clearly I read the question too fast.

Deleted because I didn’t know what was going on.

Removed by mod