under notifications each one has a dot next to it on right side. If the dot is dark it will cause the red square to appear. If you click on the dot it will turn white that will remove the red square. In you case you should find two dark dots in the notification section, click the dots or visit the thread and the red square should go away.
New Site Changes at the top of the page is where you can report issues.
Really digging the new upgrades and look. Super clean and sharp. Well done @lowlight!
www.snipershide.com