It's been going on for a while now, I did make a previous post a few months ago but didn't see any solution. I've cleared my cache and updating everything, but it seems to do this on my account on every browser I have, not just Chrome. Because the shout box does not automatically refresh, it doesn't look like I've sent a message until I manually refresh the page, and I think other users can't see my messages either.

Edit: (3rd September) Considering it's been a month I just wanted to report it's still happening, although it's been about 2-4 months now where it's still going on. :/