As of the last few days my 6S has started turning itself off in the evening without notice. Plugguing it in to charge starts it up through the boot process as ifi t's crashed off and it'll run for a short time before dying again. I've done a restore and it's doing the same thing. I know this sounds stupid and sounds like a battery dying but the thing is the battery meter isn't changing through the day and shows 100% throughout which is the issue. I'm trying to figure out if this is an issue with the software or a loose sensor from when the Apple Store replaced the screen on the device a few weeks back. Anyone got any ideas?