I don't know if it's just me, but I believe it would be more visually appealing if you didn't have the number of notifications appear if you've already opened the tab (Like Facebook).
It is good to have an unopened notification to be highlighted, but I believe we don't always need the number of notification to still be there after opening the tab.
Status:
Rejected
This number is the total of unread notifications not all items in the tab. You can have it remove by modification. Won't fix!
1
voteNotification number to disappear after opening notification tab