iPhone SE keeps locking/power cycling
Since last night, my iPhone SE has locked up completely, reset itself in the night, or just gone blank and unresponsive.
The Hard reset seems to work but as I use my phone for business it's not an ideal situation for me as I wouldn't know if and when it will decide to do this next.
There is no "Hot Button" when this happens as had been reported with the 6s...
It's running 9.3.1 and up until last night has had no issues previously...
Has anyone else had this problem?
iPhone SE, iOS 9.3.1