ASUS - ZenTalk

Asus rog phone 5

First try Reset or Wipe Data from Safe Mode.
If it work use it as longer it work and never turn off your wi-fi.
If after resetting it doesn't work then take it to service center. That mean your phone may have faulty motherboard as mine was same problem.

@rajnishkumarsingh26 
!!!!!!!!!!!!!!!! If it work use it as longer it work and never turn off your wi-fi. !!!!!!!!!!!!!!!!!!!
Very bad idea, if it is still under warranty you will exceed it and pay the full price, almost the price of the new phone.
If he has just finished the warranty, 0-30d for example, the service center will give you an estimate, write to asus to protest and take it as warranty