The reason is presumably because you have received votes from @upmewhale and @rocky1 which are very well known bid bots.

But I do not see any transactions going to that acount with a memo of your article. Can you explain why your articles get upvotes from @upmewhale and @rocky1?

If you do not know anything about them, maybe with the current settings of #newsteem bidbots upvote for curation and not for the bids. But what I am sure about is that you have received those downvotes presumably because of the bots upvoting you. Surely, it is nothing personal. Downvote bots just see upvote bots in action, so they act, too.