Lock screen keeps lighting up without prompt

Hello,

I was wondering if anybody could tell me why the lock screen on my iphone 6 keeps lighting up without prompt? I am neither receiving notification nor am I pressing any button to cause the phone to light up. My battery life is only lasting 2 hours from full charge. Please advise if there is anything I can do prevent this from happening?

I have just downloaded ios 12.1.2 (16C101) onto the phone and this seems to be what has created the problem.

Thanks in advance.