Hi, sorry to hear about this.
Make sure you are on latest software version which is .99 if not, you can check by
Go to setting => System => About => Software information.
Factory reset your phone once.
The SMMI tool is a Hardware test, just to save time you can follow above test.
Post that you can
Kindly visit the nearest service center:
https://www.asus.com/in/support/service-center/india