I tried to vote on the other answer to my question, but it says I can’t unless it is edited because my “vote” from 45 minutes ago is locked. The only vote on that answer was from well over a week ago and neither arrow next to the answer is highlighted.
I see only 1 upvote on harrymc's answer from the timeline. This plus you indicate that you're getting a message about vote being locked makes me believe this might have happened:
- Clicked on the upvote
- (Accidentally?) clicked on the upvote again, hence "cancelling" it. The system still sees it as a vote - after all you did vote on it. The vote is now locked.
I can simulate the same -
Voted for your answer
Now cancelled my vote. There's no sign of the upvote and it's locked in till the post gets edited.