Client Bug: Number of friends online is wrong

On the button that you click to bring up the friends menu, the number of friends online that it shows is wrong. I logged on, it said three friends, and I had three friends online. After playing a game, it still said three friends, but only one was online. I don't have a screenshot of it because after writing these past sentences, when I went to take a screenshot, it had updated, but that was after a few minutes.

Edit: It happened again, 2 for 2, but this time it hasn't updated. I would've put in a screenshot, but I don't see a way to insert images.