My phone (Huawei P8) is hanging. It is hanging when it's not "in use" (at least, not by me or anyone else).
When it hangs, I have to hold down the power button for 10 seconds. When it restarts it works fine. I can single press the power button to put it to standby and return from this state as expected.
I then leave the phone for an amount of time (10 minutes, 30 minutes... whatever it is) and when I return, it has hung.
It still shows the lock screen when I single press the power button.
How can I find out which app(s) or hardware is causing the issue?