Last night my phone developed the same problem, when I plugged it in to charge - but it persisted after removing it from the charger. I tried rebooting to factory mode to do the tests, but the random selecting of buttons was continuing during the factory reboot, so I couldn’t even get to the point of “item test”. Additionally, I can’t even use the power button to turn the phone off or reboot it when on - I have to remove the battery. When on, it doesn’t respond to touches at all and is entirely unusable.
I’m really frustrated, since I need my phone, and am a bit disappointed that this issue seems to be a relatively common problem. Does anyone know of any other things to check for?
I’ve sent a message to the support team too, though not sure how long it will take for a reply given that it’s the weekend.