Zenfone 3 520KL shut down

[thea22u]

Its not the first time that Im using my phone and it shuts down alone. Today, for a example, i was recording a voice message in whatsapp and it has shut down and restart it without doing anything. I dont know what happens and if someone has the same problem.
Thank you

[Christine_ASUS]

Hi thea22u
Thank you for your asking. Please try to enter "Safe Mode". If the function works well in Safe Mode yet the issue remains out of Safe Mode, please check on any disturbance from the installed 3rd party apps.
# How to enter and exit "Safe Mode"
[Phone/Pad] How to Enter and Exit Safe Mode? | Official Support | ASUS Global
Also, please try "the Factory Reset" 
Setting>System>Reset>Factory data reset
Please note that once the Factory Reset is completed, all data, apps, settings and personal information will be deleted.