Help M8 shutting off after camera flash

[Staatus_Quo]

In the past couple days, my M8 running Lollipop from Sprint is shutting off if I take a picture using the flash. It instantly shuts off after the flash goes, and when I restart it, it starts playing music as soon as it finishes booting.

Also it massively drains the battery. It will take it from about 75% down to 20% when it happens. Or if the battery is low it will drain and kill it completely. This just started earlier this week, and only when the flash is used. Any idea?

Oh yeah, not rooted either.

 

[EarlyMon]

Do a backup, I recommend Helium from the Play Store, do a factory data reset, and restore the backup.