[Q] M8 Switches off itself after upgrade to 5.0.1 topic

Hi all!

I have updated my WWE M8 (HTC_001) to Android 5.0.1 (via OTA). Since that I am facing really annoying issue.

The system itself works fine, no problems with Wifi, Vinration, etc. however it is switching off by itself.
Battery is well over 50 % charge (last time it was 88% and phone has switched itself off).
I don't know if it's the system itelsf or some app running in the background.
Today I thought I am gonna try installing 5.0.1 from scratch and I have flashed RRU via recovery, still same.
So about an hour ago I decided to root it, and I have installed Android Revolution HD 34 and problem still persists.
I don't know what is the cause of that, maybe someone has faced same problem ? Any advice would be much appreciated, cause at this moment in time I am no table to downgrade AFAIK. Sunshine doesn't support ART yet, so I have to wait for downgrade... But hopefully someone will know where is the issue ?

HTC One M8 (HTC_001) WWE
Android Revolution HD 34
Rooted
TWRP 2.8.4
Bootloader unlocked
S-OFF (I was S-ON while on KK but I S-OFF'ed again to get rid off red info in HTC error reporting)


Regards
lukasz1985