We recently upgraded our server, and reinstalled the forum software. Somewhere in the process something weird happened with the part of the software that tracks upvotes and downvotes.
The vote totals are correct, but if you look at old posts in your Notifications, it may tell you that someone downvoted your post, when in fact they up voted it. 😑
This appears to be only a historical problem; new upvotes are correctly reported. So, it's just one of those growing pains that we'll look back on and laugh someday! Thanks for your patience & understanding.