It looks like I was the next person to vote/downvote on the post judging by your screenshots - On my screen I saw the post had 71 voters and $18.45. I wish I had used the sniping tool to demo this - but I just did exactly the same as you on exactly the same post- I did a downvote, and the rewards went up by about 20cents, I undid the downvote and the post rewards went up by about 7cents and so downvoted again and they fell by 7cents. Weird. Net net the my activity has pushed up the post rewards and undone the super downvote you seem to have!That's not great - going to have to test again!
The numbers will change depending on the pool draw anyway, but taking the vests away is the more important goal than the value itself :)