Hi
ingrid.lie16Thank you for your asking. Kindly try some extra stay-at-home troubleshooting tips below:
1. As you mentioned that your phone worked some days after performing the Factory Reset, Ppease 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"
https://www.asus.com/support/FAQ/1005163/2. Take out SIM card slot>Push the slot back without SIM card>Pull out the slot and put the SIM card into the slot>Push the slot back
If the issue still persists after all troubleshooting tips above mentioned by Y_ASUS and me, please contact ASUS repair center in the country of your residence for further device checking:
https://www.asus.com/support/Service-Center-All-Countries/If it is impossible to access the service center during Covid-19 period, please try Call us:
https://www.asus.com/support/CallUs