If we have new comments on a particular entity then we have number of comments in red color there.
If we open comments then it goes away. But then if we refresh the page or go to setting and come back , again this number is there. It seems like there are some new comments there but actually that is not the case. It is showing that notification for previous comments only. If we have some new comments there, then this number keeps on adding rather than showing the number of new comments.