Share your experience!
My xa1, which is just over a year old suddenly started shutting down. The only way to reboot was to have it plugged in. It could be over 90% charged. I tried various things from taking off the last app installed, usi g I safe mode to reinstalling all software
Not finished above....
I've finally found that it will stay on if kept horizontal. When using I can turn it vertical and it works fine but as soon as it goes into standby mode, if vertical it will shut off. Is there a fix as otherwise I love this phone.
Same phone, same issue...
My Phone have been shutting down since a few days ago. I discover it has something to do with standby Mode, when in found this topic, accidentally swipe my Phone in vertical and switched off 
No sure how, but my Phone shuts down. No trouble with battery nor need to plugin to turn on.
I need a solution!
I took mine back to the O2 shop where I bought it and they sent it be repaired as it has 2year warranty. They told me it was a software issue. I've had it back 2 days and it started doing it again but this time takes longer before switching off. Will be going back again!
In the end I sent it back 3x to 02 and they kept saying there was no issue until I took it into the shop when it had turned itself off and asked them to turn it back on - which they couldn't.
They agreed to replace it but I got an AX1 ultra which is huge in comparision and heavy - not what I wanted at all. This replacement now has issues with the bluetooth. I'm falling out of love with Sony pretty fast