Issue with my phone

[Xernicus]

Hey all, I just recently (past couple of days) have been having an odd issue with my phone. It's a Sprint CDMA Galaxy Nexus 4G LTE with stock Android 4.3.

 

What's going on is sometimes when the display powers off (like the 15-30 second timer), or if I press the power button to turn it off, the phone itself seems to shut down.
I have to do a 2 second push on the power button, and it boots up with the X logo, etc... but it only takes a fraction of the time to boot, and in addition the network connection to the 4G and wi-fi are already established, and it doesn't ask for my passcode (which is currently a swipe).

I'm going to try wiping the cache using recovery mode and seeing if that helps, but I don't understand this issue at all.

Here's a screenshot of the power/usage. It says that it has been up, and on battery for about 2.5 hours, which sounds about right, as I unplugged it then. The uptime, however says only 10 minutes, which would correspond to my phone shutting off. But I'm thinking this is more of a "sleep of death"/coma than an actual shut down.

[Ann!b@l]

Are you sure you didn't booted your phone in "fast boot mode" in pressing the power button. Just in case you should go on the constructor site and download as a backup the rom matching your phone. It smells the bug. Also try to check if there's an update for the system of your phone.