Yesterday, I posted this answer: https://stats.stackexchange.com/a/350970/117812 which yielded 3 upvotes, no downvote.

My "latest achievements" (goblet icon) says that I have achieved 10 reputation yesterday, i. e. 10 reputation on this answer. I think, it should have been 30. The difference of 20 reputation is not important to me, nor do I think this particular answer was worth more then 10 reputation, but reporting a possible bug in the forum software might be important.

Is this a bug and if so, do I need to report it anywhere else then here?