Please see this snapshot. Do you notice how the points in the second post doesn't sum up like the first? Also the "+10" is missing for the upvote for "9 mins ago"
The overall total also remain unaffected. It should have been +10.
Is this a bug?
There is a maximum amount of reputation you can earn in one day using ordinary means; it's called the "reputation cap" and it's set at 200 points. Any points you earn for upvoted questions and answers after that don't count. That's what happened here: the last +10 didn't happen because you have hit the cap. The purpose of the cap is to make you go outside and get some fresh air once in a while.
Points accrued by earning bounties and getting answers accepted can earn you rep in excess of the cap.