Unsure if this should be asked here or some other SE, but I couldn't find any reference to this in the Help Centre.
This answer posted to the WB stack shows 0 reputation, but I was notified via the Achievement menu—and it still shows this a week later—a +8 change to reputation.
There are no other recent adjustments that would explain it, such as hitting the 200/day reputation change, or a deleted user, or deleted question.
Any idea what's happened?
(I gather there's something going on with moderators across the network, but I'd assume this is automated and nothing something moderators approve manually.)