Notifications dont update on second device

Hi All,

Just wondering if someone can help me...

I have an ipad and iphone 5 both running ios7 and both linked up to my icloud account

If i receive a message via facebook, i get a notification badge icon on both iphone and ipad, great!

If i then go into facebook on my iphone, the notification badge icon is then removed off my iphone, but still remains over the facebook app on my ipad,

should the notification badge from my ipad also disappear to acknowledge this notification has been seen on another device?

Im pretty sure it used to do, but not sure if ive changed a setting on one of the devices, or even within facebook for that matter.

Regards

Adam.