Hi,
The notification number (as seen in the little screenshot below) doesn’t get updated when a new unread message has been sent. This wasn’t always the case so I assume it’s a bug and not by design. It seems to act this way since the balloon icon has been removed and messages have been merged into the avatar icon in one of the recent updates.
affected version: v1.5.0.beta6 +104
screenshot:
cheers
– MK2k
What browser are you using? Can you reproduce on http://try.discourse.org (you can create multiple accounts)?
Browser is Firefox 43.0.1.
I can’t reproduce on try.discourse.org, there a number with green background is shown when a message arrives. Therefore I assume the browser isn’t to be blamed.
More observations (in my discourse instance):
even the list which opens up when the avatar is clicked does not update with either a new message (within an already created thread) or a completely new created message thread
A “like” of a post within a message thread generates a notification (the blue one though)
Not a bug then? Oh well…
Needs consistent repro steps to be a bug…
Maybe it’s not that easily identifyable and/or depends on more than just a few repro steps in the try-discourse area.
If there are any scripts / debug modules available that help narrow the issue down, please let me know. I’d be very happy to keep the analysis going. I fear however, that re-labeling a potential bug as support will add the issue to a sea of unresolved support issues 
Updated to v1.5.0.beta8 +102, the green notifications are back. It could have been an issue with sidekiq (not too sure about that however).
This case can be closed now.