I saw that I had notifications about the Group icon image. I can't remember if I did mark all as read?
Anyway, I wanted to go back to the thread to let you know it worked for me and saw that in the notification icon in the upper right hand corner removed everything...so I went to the left hand sidebar and opened up the Notifications. It turns out that I can't click on the thread to get back to the thread through that Notifications. I had to hunt it down by looking through the forum.
I'm not sure if this is by design?