I was inside a different app and I got a text message and a few other notifications. In iOS 9 they would automatically be dismissed in to the Notification Center but in iOS 10 it just stayed there until I swiped it up
In iOS 9 banners appeared at the top of the screen and alerts looked like UIAlert. It looks like iOS 10 shows alerts using a very similar appearance to banners (at the top of the screen). Banners still disappear automatically and alerts require the user to dismiss them. Perhaps your notifications were alerts that you thought were banners.
Just started seeing this on beta 4. Was fine for me on previous betas.
