I think it's normal, it's a beta.MUCH better than the first public beta on my mini 4. Still buggy, of course, but it seems way more stable. One thing I can’t get to work is “gestures”. It’s on, but swiping up with 4 fingers doesn’t work. It was in one of my reports to apple.
Now that iOS 11 has arrived at beta 9, how's about iPad mini 4?