Is it due to optimization the PM tabs or chatroom tabs does not blink if someone writes. So, unless anyone clicks the tab, cannot see if there is any shout entered or not. Earlier it was working fine but suddenly it stopped.
Are you able to reliably reproduce this issue? For instance, does it always happen after X minutes?
If you are able to give me a step-by-step guide to reproducing it 100% of the time, I will either reproduce it on my test board or on your site and fix it