@无关风月 if I understood correctly your phone just freeze and then shut off, that sounds to be mostly a software issue where the system crashes and shut off. My only advice for you is to try restarting your phone in safe mode but you may want to go directly to the next step: Do a software repair using Xperia Companion if after this the phone still isn't working properly you may want to contact your Local support to have your device inspected as it may be an hardware issue, like the battery contacts/wiring is at fault.
