Pushed this change to this forum, the notification will go away if you scroll down or after 10 seconds, and it only shows up if the topic has more than 10 posts.
@tfraley@yariplus In my case I have a new and not very active forum, so I don't visit it daily. If a spammer registers and posts something a notification would be fine.
@julian Glad to hear that it is working again.
You can see the version next to the extension title:
chrome://extensions/?id=ooeikplgcjeeggiopajfhmadglhjhcco