This has happened to me before, but I never reported it, because I was busy, but now it felt like a good time. I'm attaching a screenshot, which you can also see in full size.
As you can see, my answer has been up-voted 4 times, but I have received 0 reputation for it. I know my reputation was 6062 before I posted the answer and it's still the same.
I don't know where else to report this bug. I hope this is the right place.