iOS 9.3.4 causing my 6s plus to randomly reboot, is there anyway to fix this?

I updated my phone two days ago and since then, at random my phone will reboot. The apple sign displays breifly and then it takes me back to the lock screen where I have to type in my code. It happens about 6-10 times a day, my phone is a 6s plus. Has anybody had this issue?