User blog comment:DaNASCAT/Technical Update: May 6, 2015/@comment-2194058-20150509170440/@comment-4189499-20150509234557

I've similarly found this to be happening more this week. The notifications for a thread stays there despite having clicked and being in the thread that is being notified. On the opposite end of the spectrum, sometimes notifications for one wiki won't show up on other wikis, which has been there for at least a month now. I know a bug report should be sent in, but it happens infrequently enough to make it inconvenient to do proper testing and reporting when it happens.